1. Write a story. About really anything. Even if it's the stupidest thing or, something like this.
2. Go through your clothes. If you have any old, boring clothes (eg old white shirts, etc) maybe cut them, or tie dye them. Make them brand new and change them from your least favourite shirt to your most.
3. Redesign your room, and redecorate it. It could be as simple as moving a little furniture around, or adding decorations and furniture.
4. Get a hobby. Anything. Like scrapbooking, soccer, skating, drawing, etc.
5. Start a dream journal. Every time you wake up, if you remember any dreams, write them down in your journal. If you fill it up a lot after a while, then it can be pretty funny to read.
6. Go for a walk. Even if it's short, or around your house or backyard, just walk around.
7. Learn a new language... or just make up one. Walk around and say random words in that language, and see how people react.
8. Start a diary/journal. Write down every day and read it later. I promise you will laugh.
9. Walk around places like the park, shops, or even home yelling "bob, where are you?!" Then randomly say to the air "oh, there you are." Then hug the air. See people's reactions.
10. Give someone a glass of coke (or another drink) But when you do, fill it with salt and mix it. They won't be able to tell.