I am a 'list writer' and a 'scenario runner'. I take a problem, dissect it into it's component parts and then run little 'could or would' and take it from there.
I tend to not share it with others, usually. I'm an introvert so tend to solve things by myself, not sure why.
I definitely prefer to work on and try to solve problems by myself; I'm an introvert, as well. Sure, I'll take feedback and input from others... but most of the time I just end up frustrated with that because the suggestions imply that they actually weren't listening, in the first place.
I make a lot of lists and "on paper" trial runs of things.