Constantly believe in yourself and your product. If you feel like your product has value, you will have a lot of people who will dismiss it or say that's really cool, but that's as far as it goes. And you will have a lot of days where you are thinking, maybe this was a mistake and maybe I shouldn't be doing this. Then you will have a lot of times where your doubtful but, I would say just continue to keep the faith. Keep holding on to your belief that you have come up with something valuable. Keep pushing forward and having faith it will work out.