This is the only icebreaker that I use with my high school science students! I've used it for over 5 years and it is always my favorite day of the year. This icebreaker activity allows you to 1) talk science on day one 2) randomly group students for your seating chart 3) spend time getting to know your students and 4) allowing them to get to know you!
This is a good list of pointers to remember when decorating a classroom. I like visuals and would probably be guilty of putting up too much at one time. I loved the question "Do the walls need Ritalin?" as a reminder to tone it down!
Biology and Physical Science bell ringers (or exit slips) for high school students! The first 5 minutes of class are the most important in getting your students focused and ready to learn. Don't waste the start of class! Using daily bell ringers changed my classroom culture completely!