Never admit that you want to self injure. Staff will try and fool you into thinking that they're supportive and that you can talk to them about anything if you need to talk. This is simply not true. Admitting you want to self injure will simply get your room taken apart searching for anything sharp that they haven't already found. You'll be made to sign a contract saying you won't self injure (totally useless), and you'll be viewed as a problem and as a risk. Depending on the institution, admitting that you want to SI may be interpretted as not cooperating with treatment.

Never try to get the nurses' attention when they're on shift change. This is true of all institutions I've ever been in. At shift change they'll huddle in the nursing station and close and lock the door. Yes they are talking about you, but don't take it personally. It doesn't matter how urgent your situation is, you'll be told to come back in 15 min, and they'll hate you for disrupting them. Nothing short of physical violence on the ward will get them out of their shift change meeting.

Always participate in as much group therapy as possible. Even if you've been in the same group 5X before participate. It breaks up the day because being in a psych hospital is really boring. Plus you might actually learn something useful. As an added bonus staff really like patients who participate and appear to be making an effort to get well. It never hurts to have brownie points with staff.