One simple way to look at it is to ship things. Get your work in front of eyeballs. You can endlessly debate the value or the intelligence of your work when it's behind closed doors. Getting this work in front of other people simplifies this a bit I think.

Writing which never sees the light of day becomes far more valuable the instant it is accessible to others. The same is true for anything you create. Simply creating a blog post produces value when others read it. The key here is creating and shipping. Otherwise it just rots unseen and it might as well be some virtual thing in your head driving you crazy.

Often just doing something helps a lot. I have a friend who has horrible at photography eventually become an awesome professional photographer. I watched his progression on Flikr over the years. He started out taking a crazy number of the worst pictures I have seen. He took pictures of anything and everything and posted them all. As time went on, he posted fewer pictures but with increasingly better quality. Today, I find his pictures to be stunningly beautiful.

I have seen the same with writers and of things I do every day as well.

Just create stuff. Get it out there and don't dwell too much on how good it is. Let other people do that for you while you continue building. It's a release. You feel better getting it out there. You know you have done something because your creation is at a point where people are consuming it. If you don't think it's valuable enough, then build something else. Just keep going. Don't hold it in your head or you will go crazy.