Be willing to be wrong. Ask stupid questions. Try stuff that isn’t supposed to be tried. Question things that aren’t normally questioned. Fall on your face. Lose face. Stand up again. Try again. Run all the way through thought experiments. Don’t disallow anything, at first. Always swing for the fence. Once in a while, you might hit it out of the park, or at least get to first base. You might even bat someone else in to home plate.
“Imagination is more important than knowledge. For knowledge is limited to all we now know and understand, while imagination embraces the entire world, and all there ever will be to know and understand.” --Uncle Albert