The best advice on this sort of thing is always to scratch your own itch. Solving a problem you (and others) have will give you context and drive that solving a problem you dont have wont.

This doesn't mean you have to write your own code from scratch - that's up to you. You can pick an itch that you want to create a standalone solution for, or pick an itch where you add the solution to something existing, depending on the issue and any existing related options.