I am currently in my third and final creative writing workshop class, and all of these things have managed to transcend through each, regardless of the year, class size, professor, or focus. Workshop classes are especially good character building exercises, because you learn very quickly that criticism is a privilege. Anyone that tells you your piece is fine and s/he has nothing to critique is really saying "you are irrelevant to me and not worth my time."
That being said, here are my top 5 pet peeves for a workshop class:
1. Starting a suggestion with "You don't have to do this, I mean it's your piece, it's just an idea, but you could try..." Obviously, the writer doesn't have to do anything you say. Obviously it is the writer's piece. Creative Writing classes stress that anything that doesn't need to be said, shouldn't, and it drives me crazy when people don't follow that example when they speak. Allowing the author to disregard your idea is suggesting that he or she somehow didn't realize they had the option. I know this seems awfully insignificant, but after you hear it every class, it gets old.

2. Starting a critique with "I always love your work, and I was so excited to read this, but..." or "I really loved this piece, and I think you did a great job, but..." Again, just say what you need to say. Maybe in the 200 level class we needed to sugar coat things, but this is 450. Just give me your critique and be sincere about it. If you really love something I did, tell me, but if you tell every person that you love their whole piece to preface telling them what you didn't like, I just assume you are unreliable. If you tell a person you don't like one of their pieces, it means more when you praise the works that you do like.

3. During the workshopping of your piece, you aren't allowed to speak. Once finished, our professor allows the author to ask any questions, either to clarify on critiques they received or to bring up an issue that wasn't addressed. This is the ONLY time you get to talk about your piece, and it amazes me how many people just say "I really appreciate everyone's input, that was really helpful, thanks everyone." When it's my turn to talk, I have a list of questions I wanted opinions on; did you understand this character, was this phrase too chunky, did everyone get what was happening with this action. Maybe on the rare occasion all of these questions have already been answered, but even when I turn in a piece I love I still know there are parts I will want everyone to focus on. Utilize the class, don't just shy away from an opinion you might not like. Along those lines: don't turn in work that you need to apologize for. Don't tell us it sucks, or turn in something last minute with a bunch of grammatical errors. Respect your class and turn in something worth our time. Be proud of what you create and own it.

4. People that write about dead babies and cancer-- we want to evoke feelings with our work. I want it as much as anyone else. But cancer is sad no matter how its written. Dead babies are inherently sad. I'm not impressed if you can give me feelings because you wrote about the two. English majors tend to have this pretentious idea of their work, that everything always has to be depressing and deep and dark. Its all well and good if you can make me feel for your cancer patient, but can you make me feel for something that isn't already in a lifetime movie? It's easy to devolve into this-- my last piece was an overly cliche father/daughter bit-- but it started life as something more raw and I over thought the whole thing. I could vent for hours about how I ruined what was the first piece I had ever cried over. I understand why it happens, but...just...don't.

5. Don't look at the professor when you give a critique. This is my absolute, number one pet peeve: he is not there to tell you how smart you are as a critiquer, and you are not there to show him how clever you can be when accessing your peers' work. The author already can't speak, so eye contact is really all he or she gets to feel like a present member of the discussion. Looking at the professor the whole time, while giving direction to someone else, just makes you look like a kiss ass. Know that I probably hate you.