I plan very, very little when I'm writing. I don't actually have a rough draft for anything and just type stuff out. Once that's done, I go back through and edit things (add/remove phrases and reword sentences to avoid repetition) in a bit of clean up.
Writing was the part I hated the most about my English classes. Which is why I failed them and had to take make-up courses on the internet in order to graduate on time. I'll still be making mistakes but that happens to everyone.