my son in mixed fed. We alternate breatmilk and formula for every other feeding. I have chosen to pump my milk (it's just eaiser with my older son running around), but I only pump 4 times a day, or every six hours.We started out with exclusively breastfeeding for the first 3 weeks, then slowly introduced the formula until we were giving it every other feeding. The biggest thing we have found with doing this is that we have to keep track of what he last had because it's a delicate balance on his little tummy. Though I have chosen to pump, you could most certainly do the same type of feeding but put your baby to breast. The only main thing we have avoided by me pumping is nipple confusion, which can happen when you mixed feed. I recommend checking out this thread
http://forum.baby-gaga.com/about189119.html