Let me preface, I've played hundreds of hours on hardcore only so my views on crafting differ widely to softcore where there is no removal of items for the economy.
When should I wait and when should I create?
Wait for high ilevel items, lvl 56+ is usually a good place to start. The reasoning behind this is to make sure that your not wasting currency on low level rolls.
When should I pump it and when should I lump it?
Highly subjective, generally a good rule of thumb is to look at the possible max rolls, if you have a high potential max roll and you have a low actual roll then go for it.
When should I buy it and when should I apply it?
Easy buy currency low and sell high, play the market. Selling 1 exalt today might make you 1.1/1.2 exalts tomorrow (exchanging chaos).
When should I damn it and when should I spam it?
I assume your talking about high level items/uniques. In that case always watch the market, keep an eye out for new builds that rely on certain uniques and make your money there.
When should I whet it and when should I forget it?
Whetstones and Armour Scraps are dirt cheap (look for the 40% vendor recipe). Always max your items out. There's no need to be running around without 20% everything. Also worth noting that white items get 5% per consumable apposed to 2% magic (I think) and 1% rare.
When should I hone it and when should I disown it?
Hone always, discard rarely. In any league your characters will greatly benefit from your hand me down gear. Also there is a real market for twink gear if you have some nice pieces.
Hopefully that should help!
Vaal Skill Gem
Vaal Skills may be used only when enough souls have been collected
from slain enemies. Collected souls are saved to the zone instance
they were gathered in. Changing zones or resetting the instance will
start a new soul counter, but returning to a prior instance will
"remember" the souls you left with. Collected souls are lost if the
Vaal Skill Gem is removed from its socket.
I tested it all, everything is accurate. I never saw anything about putting the vaal gem in main weapon or something. You can put it anywhere you want.
(in your gear I mean, you pervert)
Best Answer
I've used Orbs of Scouring a couple times so far. The main use of it seems to be if, for example you find a magic item with great sockets, but, still, it's only magic. You can use an Orb of Scouring to remove the magic affixes and return it to normal, then an Orb of Alchemy to turn it into a rare item, making it much more powerful and useful than it originally was.
Whetstones/Scraps are also much more effective on normal items than on magic/rare items, so it is oftentimes worth it to Scour an item back to normal, increase the quality, then use an Orb to return it to its former level. Of course, you won't want to do this if it already has excellent affixes, as the odds of getting them back will be almost nil.