For years I have been writing `thought-books`, portable notebooks I take to school and work that I write in when I have an idea that I want to write down. I now have over 30 of these thought-books stored away.
I`m always writing, at home and at work, but the trick with me is picking out what is worthy of exploring further and which is crap. Honestly, I`ve had a lot of crappy ideas, and then again, I`ve had crappy ideas that turned out to be not-so-crappy

From there I start writing the story out, usually out on a word processor. Than I make a hard copy, edit, hard copy, edit, over and over again. It seems I`m never totally happy with my work, but I actually enjoy the whole creative process.
That`s about as much planning as I do, a mixture of brainstorming and planning.