My main goal was to make a cigarette case for a friend (who will remain nameless) because her ratty old cigarette case, so cool and unique a few years ago, desperately needed replacing.
Before I used my painted fabric, I decided I'd better practice on regular fabric. After all, I was flying by the seat of my pants, making it up as I went along. I haven't put a zipper in anything in about 30 years! My first effort turned out okay, but I was pretty sure it was too narrow at the top.
My next bags were too big, but to be sure, I had to actually go and buy some cigarettes and a lighter and see how they fit.