We already know that you can use a binder clip as a makeshift money clip to hold your cash and cards, but if you want something even thinner, an ideal clamp is a perfect solution.
This tip speaks for itself, but it’s still pretty clever. Just fold up your bills and stuff them inside the clamp. It’ll keep them organized in your wallet, and it’s about as minimal a wallet solution as you could possibly imagine. It’s significantly stronger than a paper clip, and I was even able to stuff about five or six credit cards comfortably inside. They did bend the clamp open a bit, but it only costs pennies to replace, so no big loss.
35-Cent Money Clip | Cool Tools