You got to find something thats interesting to you, then it will be easier to stick to it. My friend and I have worked on various projects from start to end, but sometimes he comes up with good ideas that have nothing to do with his interests. You can get motivated for a day or two, but it drops off afterwards.

Find something you like, and force yourself to work on it in your free time. Don't give yourself to much time either, if you have 8 hours a day there is much more to waste. Once you got a good base you can spend more time (8 hours a day) cause you'll be invested by that point.