Reading some of the crits by others will also give you a good idea of how they do their critiques and which folks you tend to agree with and which you don't.
1)It helps you look at your own writing before you submit to see what you can improve before submitting.
2)It prepares you (a teensy bit) for the kind of comments you'll see on yours when you do submit.
3)Not everyone will agree. And that can be important when you are reviewing the comments you get.
Above all, when you do submit, thank folks for their time.