Firstly- if you're store has one of the discount programs, be sure you're enrolled! After that, start watching the circulars and figuring out what's on sale that week. When it's on sale, buy it. For example, we had a Buy One Get One Free on Lysol Bleach toilet bowl cleaner this week. Well, I only use Lysol Bleach cleaner. We bought 8 and got 8 free. You better believe I don't need it again until next year. I hate paying $4 for that stuff... and if there's going to give it to me for free, I'll take it!
Next, go in with a list. Avoid the impluse buys. By having a list, you can keep to it and cut down on the impluse buys.
We have a ValuPak that comes monthly that's fabulous- everything from dog grooming coupons to free meals, etc. Check ValuPak.com and see if there's one in your area. If so, take a look.
Get your coupons organized- and be sure you know what's up to date and what's not. Divide them by parts of the grocery store. When you're making your list, highlight the items that you have a coupon for so that you know the quantity you need and the brand to save.
My favorites include coupons.com, coolsavings.com, wow-coupons.com. Also, I have a tendency to check manufacturers websites for coupons. You can almost always find them for deoderant, etc.
Be sure and check the Budget Board for the latest listings, too, for things other than grocery shopping.
It take a bit of work, but I always walk out feeling so proud when I watch the cash reguster just take off the bucks as they ring the member card and coupons through. Once you figure it out, you just tend to do it.