Work on problems worth it. You know them, you can feel it.
Get the problems clear. Build solutions that are tractable, scalable and bold. These require you to become persistent, okay with ambiguity and undistracted.
After succeeding, move on to new problems.
How not to work
Work on problems you don't care about, without change.
Work on important difficult problems without changing them to important yet tractable ones.
Continuously excuse this hesitation to change.