When I look for wands, I look for:
1. The dullest tip.
2. The most comfortable for my hand.
3. Most uncomplicated.
I remember reading somewhere that sharp-tipped wands make for black magic and casting of this spell when you want to cast that spell. Also, I think that wands that are too complicated will interfere with your magic and you might not be able to cast spells that require a lot of magic.