Have you actually found coupons useful? I have honestly tried several times over the years to be cost-effective with coupons, and always fail. My problems with coupons are 1) they're always for name-brand items, 2) they tend to be for new products vs. cheaper older ones and 3) when I compare my shopping list with a coupon list nothing ever matches. On top of this, I've found several examples (almost all, really) where even WITH the coupon the item is more expensive (price/weight) than the store-brand generic. In many ways this makes perfect sense- coupons are marketing items, they exist to get you to buy products you normally wouldn't, not to save you money on stuff you're already buying.
One tip- make sure that where you shop they list the price/weight ratio on the shelf sticker. Most stores do, they may even have to, but it really helps to compare packages of different weights at a glance to find the best deal...which is often the case when comparing a generic to a name-brand item (packaged in different weights just to confuse you). All through college I bought Hi-C juicy packs (for packed-lunches) because they were so dirt cheap. Eventually I needed more fluid, and found that "Mountain-Lightning" at Walmart is actually cheaper than the juice packs, much cheaper than name-brand, and, at least with that soft-drink, I can't tell the difference. I only drink purchased beverages with a meal on the go (easier to package/carry), the rest of the time it's water or iced tea.
I've got cheap living down to a science, but it would take all day to try and relate my insanity here.