Leave little things everywhere that remind you to be happy. One thing that I do is leave little post-its everywhere my locker, my backpack, etc that say things like “Be happy. Breathe. Smile.” Whenever I find a note, I read it and stick it in my binder- it actually helps! It may sound cheesy or whatever, but it somehow triggers the mind to think about when or where you wrote the note. Another thing that might help is quotes. Whether you get them framed, or just write them on an index card; anything works. I hung this quote right above my bed “You think what you become. You imagine what you create.” (Buddha) So, overnight before I fell asleep, that quote was fresh in my mind.
re·mem·ber
rəˈmembər
verb
Have in or be able to bring to one’s mind an awareness of (someone or something that one has seen, known, or experienced in the past).