1. I made a list with all my (good!) projects ideas
2. I tried to estimate how long each would take to have a Minimum Viable Product ready for launch
3. I chose the one with the shortest time estimate
4. I split the whole project in tiny todo items (things you can do in a few hours: like "create the sitemap", "create the db structure", "outline the homepage", "make that script" etc)
5. I put the list on my desktop in a long Stickie
6. I commit to myself to mark as done at least one todo each day
And it seems to work, I'm halfway through my project now.