State what you are allowed to do/what not to do with your instructor and your nurse.
Follow them around! Whenever my nurse gets up after charting, I jump up right along with her and am there if she/he needs assistance. Execute tedious tasks to help with their load and document everything you did (like drains, aROM, hygiene, vitals, glucose) - although in psych, you may not have to do those things (more like observe, ensure safety)
If you are questioning something of what the nurse did, don't be afraid to ask why they did what they did. Being eager to learn is the best thing along with asking their experiences/why they became a nurse when appropriate - it kind of builds a bond.
Keep your phone on silent or away, out of sight. If you need to chart, find a computer that is away from the nurse's station - some nurses tend to have their "spots" have to remember they have a lot of work to do than you realize.
Just be helpful and respectful. Treat your clinical like interviews. Have fun!