Sorry all, but I've gone through every phase of this -- from trifold to bifold to case with money clip to money clip only, but nothing beats the old fashioni rubberband bank. No bulge, no "too many bills won't fit in clip," or "too few bills slide out of the clip," no "hang on, I can find it... it's in my wallet somewhere...," no ratty worn out leather, and minimal pocket bulge.
Step 1: Fold cash in half, big bills inside, singles on the outside (any other way is just looking to draw attention)
Step 2: Insert only necessary cards in between the fold of money
Step 3: Place a fresh rubberband of proper thickness (this comes with experience) around the whole lot.
Step 4: Live life wallet-free and have access to all your cards as well as cash at a second's notice.
I know will be mocked for this; I used to scoff at my father when he told me it was the best way and that I ought to stop playing with the other methods, but eventually, five years after he first told me, it won out. Give it a try, you may like it.