Stand in a different place
My prof at grad school and a huge influence in my life even though I met him only for two years, Marty Siegel, would offer weird (of strange or extraordinary character) tips and ideas that I'd follow but never fully understood the reasoning behind it back then.
One simple thing he said was to mull over a problem by standing in a different place. I took it rather literally, and I would spend time in our backyard, in the shower, and just think over a problem.
A bit later, I realised he probably meant it metaphorically. That is, you cannot have the same patterns, the same thought process, and expect a different outcome or a different solution to the problem.
The good thing was, taking his advice literally got me to understanding the metaphor.
Try it. When stuck, or trying to think of something new - literally and/or metaphorically, stand in a different place. Look at the idea from a different perspective or lens.