Focus on the good stuff first

So you finished your first draft of a story, you go back to read it, and realize some of what you wrote kinda stinks.  Instead of getting overwhelmed by the amount of shitty writing you think you spewed out, focus on the things that did work first.  Do your revisions based on those phrases, paragraphs, or scenes that really excited you, moved the story along, and kept the tone consistent.  If you find something that turned out really well but seems out of place with the rest of the story, chop it, and save it for something else.