You're going to laugh, but I am perfectly serious:
A loose-leaf notebook, a package of divider-tabs, a small container of number-two pencils, a small pile of extra erasers, and a pencil sharpener. On a clean desk with good light.
You need to organize projects in a simple but flexible way to organize your projects, and you will find that writing things down by hand on a piece of paper is different from typing it in. You need to slow down
and think. The muscular movements needed to write a phrase down by hand have an effect.
I have a larger box with a slot in it, into which I slide the pieces of paper that I am going to "throw away," un-
crumpled. From time to time I find myself diving back into that box and removing a piece of paper that I had earlier "discarded," and it is none the worse for wear.
I repeat: I am perfectly serious. Project management is a lot
of what I do for a living, and this is
my main process, from which any Gantt charts, Project plan documents or whatever-else are as necessary produced. (When a project goes final, I fax-scan the handwritten pages and store them electronically, but there's a shelf of paper notebooks.
"Planning," I believe, is something that you
do, not that a computer does for you. A computer can certainly assist
you in the familiar ways that computers always do, but that plan,
whether meant for one person or a hundred, is going to come first from (literally ...) your hands. There are benefits to doing it slowly.