I guess I'm a little picky. I have to always have a Fire, Water, or Electric Pokemon...or at least someone who can learn Flamthrower, Surf, and Thunderbolt and be decent with it. And I usually go for fast Pokemon that look slender. I feel uncomfortable when I have large Pokemon (Blastoise, Venusaur, and Torterra, I'm looking at you). And I don't like having too many defensive Pokemon either. Umbreon is an exception, since it's my favorite, haha. Oh, and once I have my six members, I don't change them. Very rarely have I changed my party, or raised something and then decided to scrap it. It usually only happens when it's my first time playing a new region (so it'll probably happen to me in BW).