Other than breast milk, Enfamil powder formula was the main supplement we used. I mean, it was being used by our hospital, so we continued using it after bringing our newborn home. We have tried other brands and types but the Enfamil really mixes well; no clumping. I don't know why a baby likes formula so well, they all smell bad!!, but some other brands the baby didn't like at all and would spit it out. I never had that problem with Enfamil. So we stayed with the one that the baby didn't 'waste'.