Question

Which prewriting technique helps a writer organize ideas?

Answer 1

Brainstorm and then an outline. You need to find out what you want to write about and then make an outline so it is organized and flows nicely.

Answer 2

That's called brainstorming, as a very basic term.
There are forms of brainstorming like venn diagrams, cornell notes, the 'mountain' chart that writers use for plots, for some examples