This came up in a discussion with a friend of mine. She is unwilling to send her work out for publication. She is protective of it as she feels it is her best work. I understand this view as I used to be the same way. Then I realized something, as your writing improves your older work looks like shit. It’s true. You think it’s brilliant when you write it so you don’t send it out. You either a) want to keep it for yourself thinking it is too special to let go or b) don’t want to send it someplace for publication when you could have had it published somewhere bigger/better/whatever. So you keep it. Six months roll by and you read it again. Shock sets in as you realize it isn’t as good as you thought. A year later, it is relegated to the island of misfit manuscripts.
I suggest, upon finishing a work you feel is brilliant that you let it go. Yep, send it out for publication. You’ll save yourself some regret and might even get published in the process. At very least, you’ll get some experience submitting work.