Making zines, making beats, making slime. Making anything trains the part of you that makes things.

The habit of producing things is more general than the thing produced. Starting something, hitting the boring middle, deciding when it is done: those steps are the same whether the output is a track, a shelf or a jar of slime. People who make a lot of unrelated things get fast at that sequence, and the sequence is what transfers.

Count how many things you actually finished in the last month, including silly ones. If the number is low, lower your standards for a while and raise the count. Six small finished things will teach you more about finishing than one serious unfinished one.