I am very fortunate to have a wonderful critique group, made up of a variety of talented writers (editors, proofreaders, and readers). They write novels, short stories, flash fiction, and blogs, but our common theme is the mystery genre.
Here are my top nine bits of wisdom...
1. I learn as much from the discussion of everyone else's work as I do from the discussions about my submission. It's a great place to brainstorm ideas.
2. Whenever I think I am done with a set of drafts, I find I am not. I am too close to it, and I don't see some of the points that others do.
3. Cut the adverbs. Make a list of the words you use too frequently, and use "search" to target them.
4. Cut the fluff. If it doesn't move the action forward, you don't need it.
5. Cut the back story. Avoid huge dumps of information. Sprinkle in what the reader needs to know.
6. There is a difference between having a lot of activity and action in your story. You want the latter.
7. If you're bored with a section in your work, your reader will be too.
8. Critiques are not personal. They are to help you improve your writing. So suck it up, buttercup, and fix the weak points. If you are too sensitive about having your work reviewed, you are going to have a hard time when your readers start making comments.
9. Writing is hard work, and very few people get it right or polished in the first few drafts.