It is a proven fact, at least to me, that too many options, or limitless options actually stifle creative thought during the writing process. Why, you ask? Because if everything is on the table, then there is no problem to solve. If there is no problem to solve, then there is no conflict. If there is no conflict, there is no story.
It has been said of some sculptor that he didn’t know what he would carve from the rock, he would just chip away the stone to reveal the masterpiece already there. My stories will never rise to the level of masterpiece, but in brainstorming an idea, everything is on the table and that is a problem. I must begin to chip away at the everything, to get to the something I want to write.
A sculptor uses his hammer and chisel on a physical block. A writer does not use a hammer and a chisel, and while a sculptor loves a new block on which to work, a writer hopes to never have a block. He or she might use a hammer on their computer if a big enough block should afflict them. So, how do I chip away at the everything to get to the something? I use a mind map. A large blank area, in my case a computer program, that allows me to start positing statements, asking questions, and getting answers that limit my options and get me to solving problems, both for myself and the characters in my story. Every thought thrown up on the mind map is a chip away at the everything. In the end, I have the something I can work with.