Jason Fried:

During the development of most any product, there are always times when things aren’t quite right. Times when you feel like you may be going backwards a bit. Times where it’s almost there, but you can’t yet figure out why it isn’t. Times when you hate the thing today that you loved yesterday. Times when what you had in your head isn’t quite what you’re seeing in front of you. Yet. That’s when you need to have faith.

I try to keep this in mind every day.