This was my old wallet, sewn by someone who wasn't me, bought years ago on Etsy:
Meet my new wallet:
I enjoyed the challenge of figuring out those details on my own, but I should probably recommend that you just buy a full pattern somewhere, because I struggled through that challenge. And my wallet opens right-to-left instead of left-to-right because my self-installing understanding of the snap closure put it on backwards, and the zipper opens right-to-left, too, which was the opposite of my intention. I'm left-handed and I always understand spatial relations backwards and second- and triple-guess myself. A proper pattern would have helped.
Who cares, though - I conquered the challenge, I used favorite fabrics, and now I'm walking around with a sewn wallet of my own creation.