For me I am self-motivating now, but until I got this point I used several methods to get motivated:
1. I signed up for something. I started running in March and signed up for a 10K in May, which was motivation in itself. Then one in July, Sept, and then Oct.
2. Stats. I love my stats, and got the Nike+ Ipod widget and upload every run I complete to it, so check my stats. It gives you little awards for going faster, or further, or for longer. Like “You Just run you fastest mile, or 1k, 5k, 10k” etc. See my other post of my blog for how these look. And, if you are not running faster, or longer, or further, at least you will see you total distance and time increasing.
3. Seek help. Not in a Seinfeld way, but get a running partner, or join a running group. These are great ways to get motivated, having someone push you to get your ass in gear.
4. Same as 1, but for charity. Suddenly signing up for a race and getting sponsorship for a charity you care about, and getting the support of friends, family and workmates can really push you along, moreso here because you don’t want to let anyone down.
5. Come on here, there are lots of people in the same boat, all pushing you along. Same on twitter.
6. I do this a lot – buy running gear. The guilt of spending money on Nike Dri Fit clothing, and new shoes etc if you are not running will kill you. It will force you to go out and get your moneys worth.