Maybe you can only focus on 1 project at a time. If I work on only one thing I tend to drift. I need to at least have 2 different things a week and to divide my attention between the two.
I've solved it by both working on a freelancing project and a personal project a week.
Some weeks the freelancing project expects me to work 40 hours a week on it alone so I just work on my side project in the evening, other times it's only 30 so I can pour in more hours.
Don't ignore one area for too long though.
If, like me, you like working on multiple things at once make sure not to ignore a project for too long. Dropping a project that is worth dropping is fine, recommended even, but let it be a conscious decision, not a slow fade into obscurity.
Every month look at all your in-progress projects and either cut out some features and push it out of the door earlier than expected or drop something. It is worthless to work too long on a project without having an idea at all if people are going to like it.
Now go and get doing!