Here are some things everyone uses:
Toilet Paper Paper towels Napkins Deodorant Razors Shaving Cream (of some sort) Soap Toothpaste
Toothbrushes
Shampoo/Conditioner
Laundry Detergent
Dishwashing Liquid
Cleaning Sprays
Etc....
You can purchase these things for very very little. Most of these things (ok, not the paper products & laundry det.), I've bought for under $0.50. I can't stand the thought of buying these things for more, now! I will substitute something so that I can wait for a coupon, if at all possible.
Here's a picture of some necessary things that I bought today:

After I bought the items, I received $3.80 in ECBucks to use on my next purchase.
So even though I buy cereal & granola bars & Oreo Cookies in bulk when there's a really good sale, those aren't the only things you can buy with coupons. You really can get things that you use on a day-to-day basis.
Happy Couponing!
-Rebecca