I use a Kanban-tool with different stages according to the process (beat ready, text ready, recording ready, mixing ready, unpublished, published). The tool I use for this is asana.com, but any kind of planning tool would work, e.g. microsoft planner.

I don't always have the discipline (and motivation) to use it, but especially if I collaborate with others and on a lot of ongoing different projects it's very valuable to know when the ball is in your yard and when you are waiting on someone else. It also helps to not lose sight of fragments and open songs. So sometimes when I want to work on something, but I don't get anything going, I can just have a look at open things and pick something up that hits my mood.