CHAMPS is a strategy I really want to start to use regularly. I have the poster printed out from the teacher resource center across the room from my desk with the intention that I'll see it when I address the class, but I don't always follow through on it. One of my goals this year is to use it regularly to address the class before an activity. You basically walk the class through each step before each activity so that they always know the expectations.
"During this partner activity, I expect there to no noise above whispering. If you need help, you can ask your partner or raise your hand. We will be..... You are allowed to move around the room to accomplish your task, but please ask permission if your project involves you leaving the room. I will know you are participating when I see you working side by side with your partner. We will switch partners when the timer goes off."
I've found with any age group I've taught (Kindergarden, 4th-9th grade, Juniors) that you can never repeat yourself too many times and you can never expect kids to understand something you haven't expressively told them. It's better to over teach or over model than to have students confused and not following directions.