Don't you find limiting whats great about the digital workflow to be a strange thing to do? Try do something abstract or new brushset where you've not assigned "uses" to the brushes.
I tried painting a picture from an abstract mess of colour and using the transform > distort/warp tool to make it into various planes, then from there using multiply/overlay to adjust the values on locked transparency layers.
Studying seems like a weird route if you are actually stuck. Pretty result though.
painting from extraction is a good for certain kinds of creative blocks , the wall im hitting is with my overall execution , when that happens , i find it better to do some photo studios of different kinds of landscapes/materials/composition . When I do that usually my overall execution is better
again creativity really only comes from what you know . so the more you study usually the more you can pull from to create something new , painting from abstraction is great and fun , don't get me wrong .
but in a work setting it is rather risky , since there is no plan , its a high risk high reward kind of thing , most people I know don't do it . but for personal stuff I think its a fun tool as it forces you to make good instinctual decisions