If you want to be a writer ...
Learn to deal with criticism (of both the literary and the other kind)
Literary criticism can hurt. When responding to a review of your work, begin by asking if you think the person giving the critique genuinely wants to help you improve your writing - if not, ignore their comments. It's a sad fact that many critiquers are as motivated by envy or by inflexible dogmatic literary credos as by the desire to contribute to another writer's development.
Is the reviewer equipped to give you worthwhile feedback? Many people don't know how to comment on fiction, or how to express their ideas. If you've got this kind of response, feel free to ignore it too. It's not your job to tell people how to review your work (although you can always ask them to elaborate or explain some point they've made) and you don't have to take on board the advice of the foolish or the ill-equipped.
That leaves the critiques that are both honest and coherent. And if they are both, and they still hurt, the problem is probably with you.
Put any commentary aside for 24 hours if you can. Often it makes more sense the next day when your ego has stepped aside and your good sense has taken over. Often we write as though the reader is in our head, instead of writing as though we are in theirs, and critiquers can pick up this self-indulgent or self-referential behaviour very easily - and having it pointed out can really sting. Sometimes we write as though we are somebody we admire - reviewers spot that kind of thing too; and they often tell us that our work is like a 'watered-down' version of a favourite author. Listen to them - you want to be yourself, not a clone of your rave read. We can tend to write about what's important to us, without making it important to the reader too; if a comment suggests the reader wasn't engaged with the story, the writer needs to step back and see where they've failed to make the characters matter to the reader.
You may feel the commentary simply hasn't helped, or has missed the mark - if so, have confidence in your ability and ignore the comments. But if you keep getting the same kind of comments on different stories, you may have to reflect on your writing ability rather than on your reviewers' failure to understand your work. Highly innovative work is best workshopped with a small group of similar-minded writers because other reviewers may just not understand what you are attempting.
If you get commentary on basic errors of grammar and/or writing style, you've probably put your work into the workshop process too early. To avoid this kind of mistake, do the following before submitting your work for review:
1 - Print your work and read it on paper as well as editing online
2 - Look for the words; well, just, that, very, really, had, to be, then, only, suddenly. Cross them out (most are simply redundant), or replace them.
3 - Scrutinise verbs. Try to replace passive with active verbs.
4 - Read the work from beginning to end, pretending it was written by somebody you hate. Mark passages you tended to skip over due to boredom or repetition. Note anywhere it seems slow, dull, unbelievable or trite. Would you like the story if it was written by an enemy or would you find lots of things to criticise? The reader doesn't know you - they won't give you the benefit of the doubt.
5 - Name usage is key to professionalism. There should not be more than three uses of any character’s name on any given (double spaced) page unless the uses are part of dialogue tags. Like many editors I reject standard work that has more than three uses (high literature and some specialised cases like all female or all female characters can require more name uses). It tells me the writer hasn’t bothered to read the work aloud.
6 - Check your viewpoint.
7 - Unravel the various threads in your story to make sure you haven't dropped any halfway through. Are they all tied up? It's easy to lose track, especially in a long story or novel. I've just read a story in which the writer forgot to tell me who made the mysterious phone call that announced a character's adultery to his wife. That one went on the reject pile because I expect a thriller to thrill, not confuse. At the end of the story I wanted everything to be clear and that one loose end told me the writer didn't have a reader in mind when he sent the story in.
8 - After checking all of the above, read the manuscript once again. You should be through sick of it by now, so if it holds your interest, it should hold an editor’s too.
9 - Make your corrections, put it aside and think about it to ensure you have not missed anything significant. If it still holds your interest, it's ready to be reviewed.