When crit is constructive, I love it.
Sure, like most writers I would love to be told that I nailed it first try, that it's genius and no one should ever change it.
This never happens.
Well, maybe in my mind.
So often though I am just howling away by myself and getting a response is like meeting another wolf willing to duet for awhile.
There's one message I'd like to get across, though, after seeing one of my fellows in the trenches rewrite her query ten times.
You do not have to take everyone's comments.
What you need to do, when someone is giving you crit, is shut your face and listen. Don't argue. Swallow your bad attitude. If you're like me or every other author I know, you have an inner misanthrope that might get very up in arms. Even if the person commenting on your work is your best friend, expect this misanthrope to argue that you never really liked that person, anyway. Oh, and you've always thought they dress like a bag lady and smell of ham. Also, bitch, what is with that blush color?
I advise you not to give in to the very real temptation to say these things.
No writer should be so bereft of belief in their own work that they roll over and make every single change. It's important to remember that people commenting on your stuff bring their own biases to the table, and it may or may not be a bias you agree with. (to be extreme: "I didn't really buy the main character being gay. No manly man would be gay!)
Some people will ding you for things you know to be false. ("this should be shorter/longer/more sex/less sex.") If you've done your homework you already know what genre you're writing in, how much sex is acceptable, and so on.
Learn to separate wheat from chaff. Absorb comments before you rewrite. Walk away for a couple of days.
You'll get there. We all will.