Q: How do you know what to use a coupon on?
A: I only purchase what I will actually use. UNLESS it is FREE and can be donated! My rule of using coupons is that the coupon must make the item cheaper than the store brand. Before couponing, I bought mainly all store brand (generic) products. Now, my pantry rarely has any store brand items in it. If you will wait for an item to go on sale and combine it with a coupon, it is almost always cheaper than the store brand.
Many of you ask this question often, so I hope this helps someone!