Walk backwards.
If the idea of walking backwards in public is too much for you, then just it out in the privacy of your own home. Even then, your mind will have to work twice as hard as usual to comprehend this subtle change in the environment properly.
Start keeping a journal.
Each morning, write for thirty minutes. Whether you keep your journal on your computer or through the more traditional media of a notepad, it is essential that you write from the heart, as opposed to the mind, meaning don't think about what you are writing; just write.
If you are a smoker, stop smoking.
The only thing more addictive to a smoker than nicotine is routine. The smoker is drawn to the familiarity of it all. If they typically smoke while driving, then they will feel compelled to light up a cigarette each time they get behind the wheel of their car.
Move around more (jogging/walking/hiking).
Complete a crossword and/or Sudoku puzzle each morning.