It's certainly not the only way, but this basic outline of the process may be helpful:
1. Knowledge -- Study, read, learn, ask questions, try to know as much as possible.
2. Preparation -- Decide on a small area or problem, focus, gather all the physical
elements you may need.
3. Relaxation -- Give yourself space, set aside time, clear your mind of other concerns,
4. Play -- Be silly, stupid, have fun, approach the problem in every way you can think of,
even the dumb ones, especially the dumb ones, just let your mind wander, act like a
child, no one is watching.
5. Awareness -- Pay attention to your inner dialogue, ask yourself why you keep going
about things the same way, force yourself to break the rules.
6. Acceptance -- Embrace the stupid, weird, ugly, nonsense, pointless, just let it happen
without feeling that anything is wrong.
7. Record -- Write or draw or video everything, doodle, jot, make notebooks, carry a pad
or recorder with you.
8. Judge -- After you have all the ideas generated then you can begin to edit to try to
make sense of your foolishness, analyze, test.
9. Apply -- If something works even a little bit see if you can develop it further, put the
workable ideas in and play some more.
Repeat as necessary.
You don't have to do these things in order. Don't expect to have great results right away.
It takes a little time to break your mind free from the structure imposed by the outside