Ask HN: What is your productivity workflow?

I finally got around to reading Getting Things Done by David Allen (Thanks CGPGrey) and while I'm only about half way in, I understand that the basic is to have a system you can trust and dump all your thoughts into said system and then apply its methodology.

But I also understand that it can't be the only method out there or how GTD method might not work for everyone.

So I'm curious to know, what is your productivity workflow like? Do you keep ideas in a separate app? A multiple of apps? How often do you (if ever) review?