Another thing that might help you (and that can easily be improved) : writing speed.

Try writing without stopping for half an hour, and look at how much you've written and how long you would take to write those 1,667 words a day. Then train yourself so you'll write faster. (Learning to touch-type, or switching to a Dvorak keyboard can work wonders).

For instance, I can write 2,000 words an hour, which is a great advantage for NaNo.