Best place to start is with a typewriter, a box-file and a ream of paper. No computer, too many opportunities to fiddle with the hardware/software, go PPRuNing and otherwise distract yourself. These programs tend to have you concentrating on the presentation before you have any writing to present!
It gives you hard copy that you can review in bed or on the loo or in the train, less of the ability to "instant erase" (so you have to think a bit more) and you can always scan it (or retype it) when it starts to take shape. Much easier to get those good thoughts down without having to wait for the PC to boot (and then you just have to check your email of course...).
Double or triple space it, get some colored pencils, scissors and a pot of paste. You can get an excellent second hand typewriter for a song these days and they last forever (I've had my little Olympia portable for 30 years and it's still going strong).
Seriously.