Just because a brand has a coupon doesn't mean that a competing brand isn't cheaper, even without a coupon. The same thing is true of sale items and non-sale items. Most grocery shoppers are predictably loyal to one store. Don't stick to your usual store if a competitor has a great sale. Cash-in on cereal discounts.
Cereals always have coupon deals.
Organize your coupons. Store your coupons in an envelope according to category, i.e., major food products and nonfood stuff. Circle the expiration date. Stick to what you need. In other words, if you normally don't buy fancy, microwave dinners, don't buy one at 30 cents off.