It is very important to familiarize yourself with a store's coupon policy.
Take for example Publix...they offer store coupons that you can use in conjunction with manufacturer coupons. You can tell a Publix store coupon because it will say LU#(followed by a number)
I was recently able to take advantage of a great sale at Publix that resulted in me going home with 6 free bags of Fresh Express lettuce. Let me explain how it all worked out.
Publix had a Buy One Get One (BOGO) free sale on Fresh Express lettuce bags. I had some manufacturer coupons to use but when I walked into Publix I picked up their coupon booklet and noticed a store coupon saving $2 when buying 2 bags of Fresh Express lettuce. So I bought 6 bags of lettuce, used 6 $1 manufacturer coupons and 3 Publix store coupons and got them all for free.
God has really opened my eyes to using money more wisely and also being patient with purchases. If you use coupons at the right time you can maximise your savings.