Pick a topic and study (duh!)
Write or speak about it as if you’re explaining it to someone.
Repeat and simplify the language or include graphical representations.
‘If you can’t explain it to a six year old, you don’t understand it yourself.’
— Albert Einstein
Focused learning – active mental force to breakdown the concepts.
Diffused learning – let wander your mind and deal with concepts slowly in chunks.
To put it simply, take a break when you hit the bricks. Asimov always had more than one project at hand, if he’s stuck in one – he’d jump at the other to keep things rolling. To be stuck in a single project, or just focusing on the problem one may fail to arrive at the solution.