I've tried a bunch of different wallets/clips.
Tri-fold and bi-fold. Worked okay but so bulky.
Tried money clip and binder clip. Worked okay but I'd have a tendency to misplace due to smaller size area, and didn't like idea of slipping credit cards in there, so tried carrying money clip and a slim card holder. Now I had an extra thing to keep track of.
Got one of those magic wallets from J. Crew:

Holds the $$ nice and tight, 2 credit cards + DL + open slot for random card if needed. Can slip in a couple of business cards opposite the $ and it's still less than 2/3 the bulk of my bi-fold with the same contents.
Only downside is that I think the elastic's going to wear out eventually. But you can get them on sale for like $5, so if I get a couple of years out of it I'll be happy.