For all nervous and insecure creators (emphases within the text are mine):
...(c) About the work itself, to its intended audience, say merely, "Here it is: I hope you like it." And nothing else. It is neither your job to praise your own work in its presentation or to run it down when initially presenting it. Quiet self-confidence is the tone to take. Not feeling quietly self-confident / have never felt that way in your life? Fake it. We all do at one point or another. Just indicate the work and step back: let it do the job for which you created it, which is to communicate on its own...
Also :
...(e) When the cruel and nonconstructive feedback arrives -- because it will -- recognize it for just that and do not respond except with something very neutral like "I hear you. Thanks for taking the time to comment." (No matter how much you want to rant and rave, no matter how much you hate even thanking them. Be the grownup about this, since they're plainly not going to.) Do, however, examine the feedback for signs of anything that's genuinely useful to you. If there's nothing: kick it to the curb. But when evaluating, trust your instincts. Sometimes even a nasty asshole will put their finger on something that needs handling, and your duty to your art requires that you take that on board. But you don't have to take the nastiness with it.
(f) When the positive feedback arrives -- because it will (and hilariously, sometimes way more of it than usual will arrive about a piece of work that you're none too sure about) -- say "Thank you, I'm really glad you liked it!", or something along those lines -- and as little more as will go along with that stance of quiet confidence. Do not meet gushing with gushing. The squee (if any) belongs on the other side of the transaction. If it arrives, accept it gracefully. If the reader pauses to discuss at length something they really liked, you're allowed a few more words about that to say (if you like) a little about where it came from or what was in your mind. Then step back again....
The rest of this comment, which is all well worth reading, is on Ms Duane's blog:
http://www.dianeduane.com/dd-q-and-a-creation-self-esteem-and-running-your-own-work-down