
Create a menu.
Make a list of the meals you plan to make for the week: entrees, side dishes, desserts, breakfast and lunch, too. It helps to bring your menu to the store with you, because items unexpectedly on sale may inspire an amendment to the menu.
Make a list.
Look over your menu and, one by one, write out the items you'll need to buy at the store. Look through your freezer, fridge, pantry, and closets for staples you may be running low on. This includes paper products, toiletries, cleaning supplies, spices, and such.
Grab a bite to eat.
Never shop hungry! An empty stomach will cause you to drool over every cupcake, and toaster pastry you see. Your cart will fill up, and your wallet will empty, before you've even gotten the items on your list.
Bring a sweater.
Foof conglomerates are not stupid. They know that the cooler temperatures in the store tend to make you feel hungry, and thus buy more. Not to mention the added effect of flourescent lighting that causes sleepiness, which may make you move a little slower, and stay in the store longer. The longer they have you, the more they can sell you.
Bring a calculator.
Stop and do the math. Sometimes the store brand is cheaper by itself than the name brand with a coupon. Also, the deals may not be deals. Example: sometimes it may be cheaper to buy two 5 lb packages of sugar, than one 10 lb package. Also, use your calculator to keep track of your spending.
Check out the store brands.
Most of the time, store brand items are exactly the same as the name brand, but cheaper, because the packaging is simpler, there's no toy, prize, or copyrighted television character involved and there's no expensive ad campaign Take note that I said most of the time.
Clip those coupons.
A coupon organizer makes things much easier. I've recently realized that the best organizer is a three ringed binder filled with those clear plastic baseball card pages. Divide your sections according to the aisles of the store, to make finding the right coupon easier. I recommend using divider tabs that you can attach directly to your pages (regular notebook divider pages are too small to see between those card pages). If you have a 50 cent coupon for any size item, pick the smallest (cheapest) size, and you might just get it for practically nothing. But if it's an item you generally keep in stock anyway, like toilet paper, pick a larger size. Sometimes all it takes is a coupon to get you to try a new product that may thoroughly enjoy.
Find a store that doubles those coupons!
Why save nickels and dimes, when you can save quarters and dollars! Stores that double coupons daily, will often have triple coupon bonus days!
Read the circulars.
Check out your store's circular ads to see exactly what's on sale that week. Sign up to have the ads delivered right to your email inbox. You can match up your coupons to the current sales to increase your savings. You can also plan your menu around those ads. Remember: not ALL sale items will be on that list. Sometimes the store will surprise you with other sale items when you get there!

Every coupon site seems to offer the same coupons as all of the other sites every month, so there's no need to waste your time browsing around, and signing up for fifteen different coupon sites. Also, the money that you'll save with the coupon will undoubtedly be spent on the cost of the printer ink and paper that will be wasted on all of the advertising and recipes that print with each coupon. For me, it's just not worth it. But I've given you the info anyway, so that you can decide for yourself.
Here are some printable coupon sites:
Coupons.com, CoolSavings.com, CouponBugs.com, CouponSurfer.com, CouponMountain.com, SearchGroceryCoupons.com, MySavings.com