I too am a musician/songwriter, and I'm inspired by the recent Webinar on checklists to suggest that some aspects of your general approach to practice (I agree w/Mcogilvie it can help to define such as an Area of Focus) might benefit from having a checklist. In other words, you may approach learning a new piece in the same way every time (e.g. play through from beginning to end; identify "trouble spots," etc. etc.). And if it's a concept vs. a piece, you might still benefit. Perhaps it would be: "find examples of XYZ concept," learn piece, study section in such-and-such a tome..." Then, of course, there's just the list of current music-related projects.
Vague examples, I know, but jazz is such a specialised field with vagaries all its own!
So...to use said checklists, you could perhaps have a dedicated practice time, and make sure that, wherever that may be, you have access to any and all applicable checklists. That way you could actually practice what you're moved to in that moment, knowing that at least you're moving forward something that's important to you...