I work on a live document to keep track of:
* The minimal features that would make the project finished in my own eyes.
* The minimal features that would make the project interesting to others.
* The future features that I dream about.
* Articles/discussions that could spark new features.
My past self that wrote the document is my boss, my current self is the worker that tries to make his life easier and push the project thru the door by removing the extra load.
My boss wants me to work on the hardest tasks first, so these are finished before I lose momentum and we have a proof the project could work.
Now, I'm used to completely losing inspiration and getting burned out from long projects. I can focus on them for 3 months, then I'll get stuck and stare at the document the whole day, for days. At some point I'll understand there won't be any more progress so I just carefully backup the project and remove it. The feeling of removing a self imposed load is relaxing.
Months later the itch of working on that project could start again, or I might realize it's not worth. The important thing is that I won't be permanently burned out. I've finished many projects with long stops, I've learned why doing X was too difficult, I scrap the code from my frozen projects to speed up others.