If there is a specific product I need that I know there are sometimes I coupon for, I always check the online printable database. I have found many obscure product coupons on here. My favorite is the first on the list. I think it is the most user friendly. I always come here to see if there are Reynolds Slow Cooker Liners! (Best deal at Walmart!)
Another place to look while shopping at retail stores and restaurants:
*I have found that sometimes it is easier to Google "Office Depot coupons" and then find the Retail Me Not link. Just FYI.