Scrolling through social media or watching tv
Drinking too much water so that you're waking up often to use the restroom
Thinking about work or other stressors.
This one takes intentional effort and practice to train your brain! Make a list of "to do's" or talk to someone about what's on your mind earlier in the evening and then leave those topics behind until the next day. Try reading a book or doing something creative that helps your mind stay off stressful thoughts.