First you come up with the idea. Then you write it down. You read it, and you love it! It's perfect, you should send it out that very moment, right?
One thing I've trained myself to do is walk away after I write something. I may come back that same day and clean it up, but before I do anything else or let anyone else see it, I hide it in a drawer. Actually, it is on my computer, so I just close it and refuse to look at it for at least a month.
Then in a month, if I still like it, I begin work on it and share with my critique group. I can always tell when a story comes across our critique group that was written that day.
I find that I get so excited about things I often jump the gun. I'm not a very patient person. I want everyone to be as excited as I am at the very moment I am excited. Unfortunately, life has taught me that most people will not be as excited as I am at the same exact things that I am, and that is OK. Sometimes we have to take the time to get them excited, and when we do get them excited, it is because the time is right.
Putting my writing away helps me to be more objective. I often pull a manuscript out, read it and am so glad no one saw that but me. Other times, I pull it out, still like it and know I have something worth working on.
So what do you do when you first write a story?