Consumer Reports: Nickel-Squeezing Tips

Shopping

Stores often match competitors' coupons or advertised specials. When you shop at your favorite stores, carry other stores' coupons and flyers and ask for the same deal.
When I shop online, I always check Google for a coupon for the site before I check out. Just yesterday I saved $15 and got free shipping on shoes.
Many businesses give affiliation or age discounts, so always ask. Even my vet gives a senior discount.
Try to negotiate everything, not just cars. It's as simple as saying to a sales clerk (managers are better), "Is there something you can do about the price?" This is especially effective if you can find a minor defect in the item or if you're buying several items.
When we need office furniture, like bookcases, we buy it used.
Take stock before you shop. I have three bottles of Windex under the sink because I didn't look before I bought.

Food

In the supermarket, I look at the unit price. Many items such as tuna have a quantity surcharge—the bigger container has a higher unit price than the smaller one.
I bring coffee to work in a thermos.
Once or twice a year I won't buy as much food as usual and I try to empty the freezer and cupboards before buying more. The freezer, especially, is full of food I forget.
Avoid bottled water. Buy a decent water bottle for everyone in the family, put their names on them, and refill.
Cook more at home and make enough to freeze. Later, when you don't have time to cook, you're not tempted to buy prepared food, which costs more.
Buy wine and beer by the case, which is cheaper. Either stock up for yourself or split with friends.
I eat breakfast at home instead of buying it on the road or at work.
Bring a bag lunch to work. And bring your own snacks too; those trips to the vending machines can add up.
Buy kitchenware (pots, pans, knives, etc.) at kitchen-supply wholesalers. Many are open to the general public.
Grow your own vegetables and herbs. You'll save a lot (think about the cost of a bunch of parsley or thyme) and you'll use them more since you'll have them on hand.
We cut our grocery bill in half by planning next week's menu and shopping with a list.
If you don't want to cook, get takeout instead of dining in the restaurant. There's no table service, so there's no tip, and you can resist adding dessert to your order.
Eat half the restaurant meal and save the other half for lunch or dinner the next day.