This trick helps a lot. If you are building a tool for yourself, there is no need for the "motivation" part at all. You just want to make your life easier with it.
I would say keep a single project/codebase for all the tools you are building. So that there is no yet another "setting up the project" involved. Straight to building stuff.
In case you don't the tool you built anymore, there are other people still using it. If it's a free tool, having paid customers would give you a boost to work on it more.
Well, nothing is free. You still have to pay the server bills right? (also I'm hoping you are not selling your customer data and making some money secretly 🤷♀️). Let me know if you have any tips!
In case you haven't read, check out my Top 1 way to not mess up your project. TL;DR - Don't be a perfectionist 😬😆