As a writer, I know the pains of the first draft. I know even more about the pains of revision. You never truly feel done, but you have to start submitting it or at least start on a new story. Along the way, I've picked up a few tips to improve either the process or the end result.
1. Know what the goal of the story is. It could be an idea that you want your story to represent. It could even be an emotion you want your readers to feel when they're done reading your story.
2. You can't apply all of the suggestions from your critique group. The suggestions will almost always contradict AT LEAST one other suggestion. And that's OK. You want tons of different ideas and viewpoints. But, eventually, you're going to have to weed through them and see what works best for your story.
3. Take it step-by-step. If you just look at a mountain of critiqued copies of your stories, then you'll get overwhelmed quickly. You can tackle each person's critique's individually or you can tackle each type of critique individually (like focus on your characters, then your plot, then your ending, etc).
4. Have all of your critiques in one place. This may be a personal preference, but I really like taking everybody's critiques and rewriting them on a single copy of my short story. I use colored pens to keep it all separate. It's just easier for me to do that than to shift through almost 100 pages of critiques.
5. Not everybody will like it. You all are probably all going "duh" right now, but it's important for writers to keep this in mind. There will be someone who doesn't like a particular story. There will be a story that some who usually loves everything you write won't enjoy. Find out why they don't like it (It may be as simple as different tastes. After all, that's why there are so many different authors and genres) and move on.
I hope this has helped some you! I would love to hear some other revision tips in the comments.