A couple weeks ago when we went to do some grocery shopping and we kept running into this woman throughout the store and then ended up behind her in line. And it was an experience.
She had things out on a spreadsheet and then had an expandable file in her cart (not just coupon size - but big file paper size). She not only used coupons but she did price matching for stores. So she had things all grouped together on the check out counter - for each store and she would tell the clerk the store and price as he picked up things. And then at the end she had coupons for most of those things too.
So such as Walgreens had Gillette Fusion Pro-Glide Razor System on sale $9.89 and their rewards program brought it down to 4.89. (which I guess Walmart will match that price) And then she had $4 coupon for it too. So she ended up paying 89 cents for them. And she had 4 packs and 4 coupons so got 4 packs at 89 cents each.
We were talking to her - she ended up with a 98 dollar bill which would have been 300. She told us that last week with her coupons being doubled and tripled at another grocery store that she paid $37 and it would have been $115.
Now I have always prided myself on being a pretty frugal shopper. I get all the sales. I compares prices at stores. And use some coupons. Make things instead of buying things - such as make a cake instead of buying a cake mix. Buy store brand instead of name brand when cheaper. And all that good stuff. But her method really did give me pause to maybe I should be doing MORE.