I try thinking about life, I start imagining my video game I like and other hobbies, I start imagining sad things and I'm trying to avoid imagining them.
I'm basically getting further into my mind and usually I end up sleeping, probably because doing it makes me feel better and passes the time, relaxes the body so the brain can finally turn asleep peacefully. Sometimes I simply give up and pick up the mobile phone to pass the time until I decide to try once again to sleep.