I've crafted items that give me strength and intelligence which seem like a waste if I'm a monk so should I salvage the item and try again? Is there a way I can influence this so I get items that have magical properties I want?
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.