I make notes for each project in a google doc, i.e. collecting material as if I was going to do a write-up or talk on the project. That makes it easier to set t

I make notes for each project in a google doc, i.e. collecting material as if I was going to do a write-up or talk on the project. That makes it easier to set things aside for a while, and if you discover something by accident while you're not working on the project, you can make notes in the document to return to.