Two things that help me finish long term projects.I found if you work on the project every day a little bit it gets done.You don't have to actually work on it just doing research helps make progress. The other is to farm out work when needed. I like to do as much as I can myself but sometimes due to time, skill, work or family it is best to have a pro do it.
Sometimes I wish I could hand off some of my projects but then it wouldn’t really be “my project” to have pride in. Kinda be like selling everything and buying a new Challenger and sitting on a chair at a car show with an umbrella drink in my hand saying hey look at my car.