Most of the previous posts cover most of my personal strategies. I have a few unfinished games which I stopped working on because the concept wasn't as good as I thought once I got going. I usually mull over game concepts for a while before I start anything. Overall my strategy for finishing games is to keep in fun , take small breaks of a few days (play other games etc) so that you don't feel your game is like a job. Keep your game small at first and work specifically on each area until you feel you have a good foundation . I usually work on game mechanics before story (an example). I never bog myself down (since I do my own art) with one task so it never seems to get boring. I use a lot of randomness in my games as well. I also try to keep my game mechanics as simple as possible I don't try to build too much complexity as that is a project killer. And of course the last thought is once you have finished a game that game becomes a resource for your next project.