Coupon Files and Organization

To play the Great Grocery Game, you will want a very large stock of coupons; the more you have the more you save. Early on you will recognize you need a file and a good system to organize them. It makes filing coupons easy and you can quickly find the coupons you need. I recommend an expandable cancelled check file. It can hold hundreds of coupons. I organize the file's 12 pockets by product groups. Question: How do you file your coupons?