I have a very hard time weathering the enthusiasm storm. When I write something, I usually get really excited around draft two or three. I think my story is fun, exciting, fresh, different, brilliant! Ready to be published! Of course, I'm wrong. But it takes a great amount of will power and patience to not just shuttle that little baby manuscript off to agents and publishers right that very moment!
I have learned that I need to step back. Let the words rest. Get my critiques in from my groups. Revise, revise, polish, revise. Do my agent/publisher research. Then revise and polish again.
Even after all that, I have regretted submitting the occasional manuscript too soon. The magical "it's ready" is a very elusive thing. Spotting it is not a skill I've mastered yet. But I'm making progress. How about you?