Use what you know, it is the least likely to get in the way. I use vim if for no other reason than it saves me from cleaning up the errant ":wq" and the like which end up scattered throughout anything I do in any other editor. If you use any sort of markup realize you will have to get rid of that if you decide to submit it anywhere, most journals and the like will specify how they want it formatted and starting with a plaintext or rtf file saves a step for you, I suffer with libreoffice when I submit somewhere since they generally want word or pdf and it handles the conversion easily enough. Most of the places I submit too specify fonts and sizes as well so going through the work of doing pretty layout serves no purpose for me.

* Vim and probably Emacs (I don't use Emacs but I understand it has some good points). You can write in latex, html, markdown, asciidoc, docbook ... pick your markup language.

* FocusWriter is a nice, configurable distraction-free editor/light word-processor.

* I hear good things about Scrivener, which seems to be like a really good code editor for prose.

Personally, I write in Vim + HTML (which is a pretty full-featured and reasonably light markup language if all you're doing is writing).

I recommend sublime text. Been my text editor of choice for long form writing and notes. Across work and home computers, windows and mac OS.

For writing on the phone its Google docs. Then copy over to sublime.

Everything is checked into a git repo.

Some are markdown formatted for publishing.

Low-tech. semi-automated. Works for me TM