I was confused about veil style too. But here are the things that helped me decide:
1) my face is a bit round, plus I'm doing an updo. This means my veil needed to be more "flat" around me when it falls from my hair so I don't look too fat.
2) My dress had tons of decorations in the back, so I didn't want a veil with too much lace/gems/pearls to cover that up.
3) The dress is ivory with beads, so I went with a pearled edge, ivory colored veil
4) My dress has a long train, so I didn't wanna drag a cathedral veil around along with my train
5) I'm 5'8", so I definitely didn't want a short veil. I went for something that falls a bit below my waist.
So the veil I got was simple, 2-tiered, ivory with a small pearly edge. I didn't need it to be a designer veil, so I ended up buying it at Downtown LA for like $25... It really compliments my dress well.