I didn't use much formula with my child because I chose to breastfeed my little guy. We did have to supplement with a little formula when he got older and I was working and couldn't keep up the supply. I remember signing up for all the new baby deals and getting lots of coupons and a few samples. I did use the formula coupons a few times, but wasn't on the coupon scene fully at that point so I never found where the best savings were for formulas.
Stacey at Frugal, Faith & Family has a good blog explaining where to get the best buys on formula these days. If you're at this point in life and formula is a necessity, please check out her post. It could save you bundles. Thanks Stacey!