Middle School Science: My bulletin board last year. Now to come up with this year's.....
Closed Circuit and Open Circuit (I can't find the specific post, but you get the idea--It's genius)
Emoji Lesson Scale - Relatable and current. Students leave a post-it note next to a number/face to rate their understanding as they leave class. (image only)
I have this written on my clock but it is hard to see. Will have to change it to this.
Kate's Science Classroom Cafe: Absent and Extra Help Bulletin Board
Science classroom door decorations
"Today for class you will need" section with pictures of supplies is brilliant.