I tried using one of those "coupon organizer" wallets a few times. It always ended up taking up lots of time trying to decide what category all the coupons should go in. And then the darn thing was too big to fit into my purse and I'd leave it at home, etc. Then, if I did remember it, half the coupons I had filed so meticulously would have expired by the time I tried to use them.
So, what I did, was just start putting them into the cash 'slot' in my wallet. I rarely have more than about 25-30 coupons at any one time anyway. I don't cut every coupon I come across, just ones I will actually use and would buy even without a coupon.
When we did the DaveRamsey course, the package you get with the class includes an "envelope wallet". I started just sticking my coupons in the front cover, loose. Since half my coupons are printed from online, they are all difference sizes and shapes, so it is easy to find what I am looking for. And I generally know if I have a coupon for something I plan to buy. The wallet fits right in my purse, and that is where I keep it. I set aside flyers with coupons on them to clip all at one time about once a week. When I clip what I will use the rest goes in the trash and the clipped ones get stuck right in my "envelope wallet" and goes right back into my purse. I have to get it out anyway when I go to pay, so the coupons are in my face and I don't forget to use them.
Oh. I keep my restaurant coupons in the BACK of the envelope wallet (behind the actual envelopes). And I keep my Bed Bath & Beyond coupons in my glovebox in the car. They never expire (despite what they say on the coupon... they will accept them even YEARS old) and I never am without a coupon for the store if I need something there.