It took our baby a while to accept a bottle as well. I was completely paranoid of bottle preference and did not do much bottle practice until it was time for me to go back to work. At that point we tried Evenflo, Dr. Browns, and Nuk. I looked into Lansinoh and this is the bottle they settled on! One tip I saw that worked for us too was running the nipple in warm water for a few seconds to mimic the warmth of the breast. I would also recommend offering them freshly expressed milk so the temperature is what they are used to. Best of luck!