Always check for items on sale and use coupons for those, you sometimes can get stuff for free especially if your store doubles coupons.
Also check your stores website, a lot of the time they will have electronic coupons which you can attach to your loyalty card for instant savings.
Also, be on the lookout for extreme couponers in your area! They often have blogs and tips on easy coupons to procure and deals in your area.
One of the main sites we use in my house is www.afullcup.com . They have great forums and easy to print coupons!
I get a lot of my coupons from emailing the manufacturers of items I purchase a lot. This is a great way to get HUGE money saving coupons.
Be aware of your stores coupon policy as well!