As a self-employed person, this is essential. I'm constantly using Things3 to take down notes on ideas for things I want to do, or could do. But there's only so much I can do in my waking hours. So when it comes time to "prioritize" and make my plan for the week, I throw everything that's not on fire in a secondary list called "brain vomit" that I simply never look at, while filtering out the important and urgent stuff to the main actual list of things I'm actually going to do.

This probably sounds insane but it's working for me. I think part of the reason is that I often don't have the mental bandwidth (or discipline) to recognize at the moment of task creation whether something is a good idea or not. I'm simply moving too fast, multitasking too much, to make those calls. So I batch every new idea into the inbox and review it later. And even if I discover good ideas in there later, if they aren't essential to my work or life they go in the brain vomit folder. So I get all the satisfaction of stream of consciousness "ubiquitous capture" (a la GTD) without the emotional burden of having to actually do all that non-critical stuff.