I like to leave myself little reminders to tell me to go work out or remember to eat healthy. the times when I need this most are in the morning, so I leave a note to myself taped to my alarm clock to remind me to go running when I wake up.
before I go to bed, I write a note in big bold letters to tell myself to get up and go running early in the morning. then I tape it over my alarm clock so I have to move it to turn off the alarm. it helps to remind me of the reason I am up at 6 in the morning in the first place. :)