Use coupons when items are on sale to maximize savings (check first that there aren't restrictions on the coupon).
Or use more than one coupon.
Some stores, such as Target and Walgreens, allow you to use manufacturer's coupons in addition to their own for additional savings (stacking). It's worth researching stores in your area for maximum savings.
Hobby stores (Joann and Michael's) also allow you to use more than one coupon. Read the fine print.
How to Stack Coupons
See more ways to stack coupons here