I don't do extreme couponing but I do check out Target and Walmarts on line coupons. I basically stick to high value ones like $ 2. and up. Sometimes there is some for me but, mostly I see coupons for OTC items with high values, diapers, baby formula, depends, ensure, stuff like that. I don't use any but figure they are expensive and someone can use the coupons. When I'm in the store I place them near the item so someone will benefit from them. I hate to see anyone pay full price. Often when I am doing my own shopping I find someone has been nice enough to leave their extra coupons which I can use. I figure what goes around comes around.
I've seen some of the extreme couponers in the store with a satchel full of coupons - one for every product for their entire cart, believe me you don't want to be in line behind them.