Often, one of my next actions is 'brainstorm ...'.
I do it, and check it off -- but the next action following the brainstorming doesn't occur for a few days, so, the next day, thinking of the upcoming next action, I revisit the brainstorm and flesh it out a bit.
And maybe I do it again.
That is, 'brainstorming' is never really over -- even when it is complete, it can serve as an excellent 'seed' or starting place for further brainstorming.
How do you bring closure to such a task? Or do you leave it open and make it a project that ends when you run out of time?