hi, after having been in the same situation, so far so good I've done this: I put in my jeans a "mini wallet", I put in there only the most most Most essential stuff, like an ID card, a bank card, drivers license and that's it, and maybe some money. I put it not in the back of my jeans, but in a front pocket, so it is always with me, ALWAYS. I also put a pen (always handy), and my cellphone (a very little one). After finishing using them, they go back to the pocket. In a few days it'll come second nature
I used to have this huuuuge wallet, filled with every paper I could think of. !I even sometimes had difficulty trying to close it!! ! Anyway, it was so bothersome that I started to left it at home
what other methods have you tried?