Write every day for at least twenty minutes. If you get stuck while writing, jump ahead to another scene, or ask yourself questions that need answering in order to move the story forward. If you get really stuck, take a break and work on a different piece, and then come back. I also find that taking a walk clears my head and helps me put my thoughts together.
Write because you love to do it and not because you care what people think. Your joy will come through.