Diablo – How to always see all items on the ground

Watch the auction house.

Right now, crafting materials are selling for substantially less gold than all but the worst low level blue items. You'll get far better results selling your blue items and buying Essences from the AH.

For example, current market value for normal mode mats is 20g for Subtle Essence and 45g for Fallen Teeth. So any item worth more than 25g, I sell. If its worth less than 25, I gamble for a shot at a tooth.

There is no way to influence the magical properties, random is by definition random.

As far as salvaging items to try again, as you play the game you'll get more and more items that drop. Salvaging the items may not be a bad idea if you're trying to get a certain combination to appear and you may not be able to sell the combination for gold, for example an item that has both strength and intelligence doesn't really benefit any one class very well, but strength and vitality is an awesome one that you cannot use, but a barbarian will. I would salvage the former and try to sell the latter.

Another handy tip is if you have a bit of extra money, the NPCs that sell blues for low prices can be used to get salvage materials for cheap, although just through normal play you will have a lot of blues that drop from champion monsters and bosses.