I have found that I must organise and plan first, in order to be able to write at all.

Some people like to use computers for that, I find that 3x5 cards on a big table top
allow me to see the big picture at a glance and that is is easier to move cards around
to put related ideas close to each other. It is also easier to find holes and duplications that way.

As to the actual writing, once that I have the research done (or a world built for fiction) it is far
easier, faster, better, cheaper, to use a pc. With a keyboard I can get in the zone and words flow
from my brain to the screen far faster (and much more legibly!) than if I tried to do that part
writing by hand with a pen.