I had a personal trainer who I was not crazy about. There were a lot of things about him that drove me bananas. However, he did do something now and then that stuck with me in a good way.
He told me that whenever I was down or had unscheduled time, just go to the gym. He said that I don't have to work out, just sit there and see what happens. So I've done that and what usually happens is that I end up working out. Sometimes I sit around and chat with people and play on my iphone and all that, lots of wasting time, but then more often than not I end up thinking, well, I'm here- I might as well put in a half hour. Similarly, if I just put on my gym clothes at home, I can usually end up getting myself to the park or gym since I've taken the time to dress for it