Looking at other blogs. As soon as I get my site overhauled, I'll put up links to all my favorites. Until then, a few are: Money Saving Mom, Deal Seeking Mom, and Be CentsAble.
Checking the Hot Coupon World database. It's not always up-to-date, but it's a great place to start. Put what you are looking for in the box labeled description. Both general ("toothpaste") and specific ("Crest") are fine. You can put in the type of coupon you're looking for (choose "printable" from drop down menu).
Check my sidebar. You can scroll through the coupons or click to see them all. They change pretty regularly. Be sure and grab the good ones when you see them. Cereal coupons for $1 off show up pretty frequently!
Looking on manufacturer's sites. They want you to buy and become loyal to their products, so they give you coupons to encourage you! If you see something on sale, look up the manufacturer and see if they have a coupon.I very rarely use a coupon on an item at full price, unless it is a product we would buy at full price. For example, I have used Clean & Clear facewash for over a decade. I usually buy it at Wal-Mart. I googled the manufacturer's site and sure enough there was a Clean & Clear coupon for $2 off any product (and I could print it twice)! Since this is something I will buy whether or not I have a coupon, the coupon (and it's a big one) is just money in my pocket!
Hearing from YOU! Try searching for manufacturers of products you are loyal to or will be buying anyway or found on sale. Leave a comment and share what you find!