How do you motivate yourself on your own projects? I tend to start something, then never complete it...

If they are my own projects that make (or will make) money, then that is enough as motivation.

I don't need motivation for open source projects - I just do it for fun - just like many millions of other developers do. It's just nice to give something back to the community. Without these we wouldn't have hundreds of software projects like Gimp, Inkscape, Wine,....

That's a sign of a real programmer.

do it like if you would quit smoking - tell everyone about it. maybe from time to time your friends or relatives will ask you about your progress and gain motivation by not wanting to be embarrassed telling them you lost track or interest in doing it.

it is simpler than that.. move your ass, bring a cup of coffee and start coding and make a beautiful piece of code and program..

Find something you're excited about. A lot of the projects I pick up I try to create something I will use frequently, and then I try to learn a new framework while doing it.