Mundane Item Crafting, Step-by-Step
These rules use exclusively the Player's Handbook and Dungeon Master's Guide. I'll gladly upvote answers that take on official sources beyond these.
- Get artisan's tools (PH 129) (5 gp; 5 lbs.). Luckily, you might only ever need one set, though check with the DM. The description says that a set "includes the items needed to pursue any craft (except alchemy)." It says any craft not all crafts, so making characters buy artisan's tools for each Craft skill specialty isn't just the DM being a jerk. But you should always have artisan's tools, as it's better to be safe than sorry. Making Craft skill checks without artisan's tools means taking a -2 penalty to Craft skill checks "if you can do the job at all," which is code to permit the DM to say No when a naked character tries to use found improvised tools to make a Craft (gemcutting) skill check ("Axebeard MacDwarf'll just hit the raw diamonds with other raw diamonds!") or a Craft (painting) skill check ("The human body contains over 30 different fluids—one must be puce!").
- Determine if the Craft skill is appropriate. If the plan is to make a spoon, and only the Craft (weaponsmithing) skill is available, ending up with a weaponized spoon, while possible with a generous DM, is unlikely. What skills can be used to create certain items is sometimes hotly debated (note the lack of ammunition on the PH 71 table), and it's debatable what some Craft skills mechanically even do (e.g. Craft (gemcutting)). Further, the Craft skill encompasses making works of impractical art, meaning the painter and poet use the same rules as the blacksmith and stonemason. (By the way, alchemical items can only be crafted by spellcasters; that's shameful and should be house-ruled, but that's what the game says.) Anyway—and finally—whether it's the Craft (mapmaking), Knowledge (geography), Profession (cartographer), or Survival skill—or any of those!—to create a new map (maybe even one suitable for framing) is a mystery. (In my campaigns, I like creatures to use the Craft (mapmaking) skill because that lets them sell maps they've made, but ask your DM.)
- Determine the item's price. Usually, this is available. If you want something masterwork, add the masterwork cost to the item now; adding masterwork is not possible post-crafting. Sometimes, however, you can't find a price. Art objects (DMG 55) are particularly weird, essentially letting the crafter set the price for the finished item. How far down the weird little crafting rabbit hole the DM wants to go might mean craftsmen who make embroidered-and-jeweled gloves always make embroidered-and-jeweled gloves priced between 1,000 and 4,000 gp. (My cousin the painter tells me art prices depend on where the art's sold not on art quality, so being able to set the price of her art before she started would seriously blow her mind.)
- Buy raw materials. Raw materials are usually purchased, and usually cost one-third the price of the finished product. DMs of realistic campaigns will quantify raw materials (e.g. greatsword raw materials, oil painting raw materials, etc.), DMs of cinematic campaigns won't (e.g. Craft (weaponsmithing) raw materials, Craft (gemcutting) raw materials, even just raw materials proper). Crafting in D&D 3.5e is such a chore I argue in favor of generosity and the cinematic.
- Determine the Difficulty Class (DC). The key is using the chart "or have the DM set one." The PH has nothing higher than 25 (71), and I can't find in the DMG any higher than 40 (76), so talk the DM down if he sets DCs at 120 or something… or don't; see below. If you must, have him compare anything to the crushing wall trap (DMG 74), which is only DC 35 and explain how you're painting the duke's portrait, not building a death machine (unless the duke's portrait is a death machine… then never mind). The crafter can choose to increase the DC by 10; this will craft the item more quickly but, obviously, make success less likely. Ask the DM if this +10 can be added multiple times; I allow it as a house rule.
- Determine how much time's available. If you only have a day, convert the item's price to copper pieces (i.e. multiply its gp price by 100). If you have a week, convert the item's price to silver pieces (multiply its gp price by 10). As a house rule, I let PCs also track progress by the hour (i.e. multiply by 800); less than an hour I rarely bother with unless it's something weird like a flirt sketch.
- Make a Craft skill check. The DC's already been set. Success means you've spent raw materials and have made progress. Failure by 1 to 4 means no progress. Failure by 5 or more ruins half the raw materials (even if you're working by the day). I'd suggest taking 10, but the DM may rule that doing so is generally impossible (e.g. "Crafting is always stressful") or impossible given circumstances (e.g. "It's difficult to work whilst the orcs whip you").
- Determine progress based on the Craft check's result. Multiply the check's result by DC needed to craft the item; that's 1 week's progress toward the item in silver pieces, or 1 day's progress toward the item in copper pieces. If you meet the item's price, it's completed. If progress is double the item's price, the item's completed in half the time; if progress is triple, one-third the time; and so on using D&D 3.5's rules for multiplying (PH 304).
Let's Craft Scale Mail!
Axebeard MacDwarf is Int 10 with 7 ranks in the Craft (armorsmithing) skill. He has masterwork artisan's tools. He has a +2 racial bonus to Craft skills related to metal, and there's metal in scale mail. His total skill bonus for the Craft (armorsmithing) skill when making scale mail is +11. MacDwarf buys scale mail raw materials, costing an inconvenient sum that the DM permits him to acquire for only 16 gp. The DC for making scale mail is 14. MacDwarf has a week, so he takes it, converting the 50 gp price of scale mail to 500 sp. He takes 10 on the Craft (armorsmithing) skill check for a result of 21. He's made 21 × 14 = 294 sp of progress on his scale mail. Give him another week, and he's done. If he wanted to—or if he was interrupted—, he could track progress by the day, and by taking 10 make 294 cp of progress per day; it will take MacDwarf more than a week if he takes individual days to complete the scale mail at that pace, however.
Let's Craft A Picture of That Lady!
The Crimson Lothario wants to impress a lady. He is Int 18 with 10 ranks in Craft (painting) and has Craft (painting) artisan's tools, for a total bonus of +14. Crim set his own price on the painting of 100 gp, and the DM lets him spend only 33 gp on raw materials. Crim's player asks the DM what the DC for nice painting is. The DM consults the table on PH 71 and picks 15. Because he doesn't have a model to work from, the DM rules Crim can't take 10. Crim wants to work by the day (he's got adventures to go on, after all) so the painting's value in cp is 10,000. The first day he spends painting Crim rolls a 15 for a result of 29, making 15 × 29 = 435 cp of progress on the painting. After he returns from an adventure, he has a week off, so he paints and rolls a 3 for a result of 17, making 15 × 17 = 255 sp progress on the painting. Hey, a few more weeks (like, three) and he'll be done.
"Wait a minute. That means…?!"
If you've gotten this far, you might have noticed some—let's be fair—strangeness in these rules. You've noticed that the higher the Craft DC of the item (i.e. the harder it is to make), the faster it can be made. So setting DCs arbitrarily high isn't always bad thing if by taking 10 the craftsman can still beat the DC. Yes, that means most DMs will rule it's faster for a craftsman to make thieves' tools than it is 10 ft. lengths of chain because most DMs will set the DC for the thieves' tools higher (probably a high quality item) than the DC for the chain (probably a typical item).
That's kind of okay. The number of folks who can consistently make lengths of chain far outnumber the folks who can consistently make thieves' tools, so it's not like there's a thieves' tools glut and chain shortage or anything. But it is still weird.
Welcome to D&D 3.5e economics.
"O, that's too much work!"
You're right. That's why there are shops. But, besides that, you can make it less work. Untrained hirelings cost 1 sp per day, and the Craft skill can be used untrained (PH 64). Your hirelings will need artisan's tools (probably) but using the rules for aid another (PH 65-6) should allow you to simply buy success. The DM may limit the number of assistants you can have (perhaps to just 1 if the DM's stingy about the bonuses from favorable circumstances (PH 64)), but it's an option, especially if you're that close to being able to beat the DC by 10.
The best way to speed this process is via the spells fabricate [trans] (PH 229), minor creation [trans] (PH 253-4), major creation [trans] (PH 252), and true creation [trans] (SpC 224). The DM, however, when using even these spells may still mandate appropriate Craft skill checks for complex items.
"But where does firewood come from?"
You chop wood with an improvised tool and use the Craft (carpentry) skill check untrained. Firewood costs 1 cp; fractions round down; one-third of a cp is 0 cp; raw materials are free. The DM rules that crafting firewood is DC 5. Spend the day karate chopping trees, taking 10 on the Craft (carpentry) skill check for a result of 8 x 5 = 40 cp of progress made per day (essentially, you're making 1 check every 12 min.). Make 40 cp (800 lbs.) of firewood in a day. Sell that firewood for half price (as per D&D Econ 101) and earn 2 sp. Buy a poor meal (1 sp) and 2 mugs of ale (8 cp total) and put the remaining 2 cp away for a rainy day. Congratulations, peasant. You're alive. I hope your family home isn't threatened by an owlbear so you can continue to take 10.
Don't pretend you're a rogue, because Ardents don't look good in leather. You require some real (and exotic) metals between you and the enemy. The thicker, the better. Ask for some mirrored or hydra layered plate platemail +5, as it's in a similar theme to your original gambit armor.
Item materials are also important and scale by half-tier1, but your main problem is that you're in leather armor with a dex of 16... in epic. The choice between heavy and light armor becomes critical.
Ardents use heavy armours because they, typically, don't invest in being fast or thinky. Furthermore, alternative materials don't cost more, only the enchantment matters.
The calculation should be 10 + half-level + material&type + enchantment + feats + ability score if light armor.
Displacer armor is for cloth leather or hide. Looking at the Ardent Handbook, you should be in heavy armor, not light armor.
Given that you're using leather, you should be using Anathema Leather or equivalent (adventurer's vault) to give you an extra +3. However, you're an ardent. No ardent should be focusing on int or dex, and ardents don't get off-stat bonuses to light armor.
Displacer Anathema Leather Armor brings your AC to 10+24/2+5+3+3 = 33.
Assuming you stay in chain, taking the boring Veteran's chain, in the +5 version, we get a
Veteran's Weavemail Armor +5 +5 enchantment, +10 from the weavemail. or +15 from the armor. 10+24/2+5+10 = 37, which for a shieldless leader designed to be in the second rank... is not horrible.
Assuming you invest a few of your feats into AC (which is only reasonable, considering that you're in melee with a con focus), You'll be in nagascale scale armor (+11 armor bonus) for a 38. And since you've got a 15 strength, you should have jumped into plate into epic, and +5 layered plate (+12 from armor). Add in armor specialization from paragon for a +1, and you've got a neat 40 AC.
Enemies, at level 24, should have around a +28 to hit. They will have approximately a 38 AC.
Additionally, you need to give enemies a strong incentive not to attack you or be next to you. You should have, as your at-wills, Unsteadying Rebuke and Violent Upsurge. Make it clear to the first enemy who attacks you that a) they'll get slid to the bad place on their turn, and b) they'll have all sorts of bad bad vulnerabilities. While it doesn't make up for your barely-there leather, it at least acts as a very vocal discouragement to attacking you. Which, when combined with demoralizing strike means that enemies will think twice before getting near the scary scary scary person. (Or, y'know, try to focus fire you down and kill you.) An AoE of "Here, have -6 to defenses" combined with an immediate reaction slide will inspire great fear in the DM.
1According to Andras, Heroes of the Fallen Lands, page 325, has eliminated that requirement entirely, and just automatically scales armor by tier. Take this as another reason to be using the character builder to generate your character sheet.
Best Answer
Let her "craft" it!
If the player just wants non-magical hide armour, then you can allow it, no problem. Getting "free" non-magical armour is so entirely irrelevant to D&D 4e's economic balance that it really isn't worth worrying about at all. Role-play it, but don't make it cost them more than the item costs. You're basically handing out 6 gold pieces worth of treasure. Hide armour costs 30g and items sell for one fifth their value; so if you really have to track every last gold piece, trim 6gp out of that level's treasure parcel somewhere else, or have the player spend 6gp on crafting supplies.
If the player wants magical hide armour, you can do that too. D&D 4e is extremely "gamist" rather than "simulationist" so it doesn't really care how players get items, it mainly concerns itself with the combat effects of the items dispensed to players. This leaves DM's plenty of room for creativity in terms of dispensing loot, and crafting is certainly one way of doing it.
You're meant to give out a number of magic items equal to the party size minus one, so if you have a party of five, you give out 4 items each level. There's no hard and fast rule that the magic items HAVE to be gained as loot or in dragon hordes: crafting them is perfectly viable.
On the most basic level, you can have that player gain Magical Hide Armour +1, and that be the group's level 2 item, leaving them with three more magic items for the first parcel. But that's kind of boring, right? Alternatively, turn this into some kind of quest: having to obtain some magical materials in order to properly treat the hide in order to impart the magical powers into it. There's nothing better than a side-quest to keep players engaged!