Honestly, my starting outlines have been brainstorming of scenes and major plot points, which I actually write down on paper. Then I develop a rough Table of Contents. I list chapters and hypothetical titles as I envision the book in its final form.

Then I start writing, and any resemblance between my final draft and the original TOC is purely coincidental.

Sometimes when I am stuck, I will use the pen-and-paper method to try to outline a little bit ahead at a time.

But that's pretty much it - mental maps and brainstorming on paper. And a long-term vision in my head. Anything more sophisticated, like all the various writing software out there, or techniques other writers recommend, has never done much for me.