When I'm writing, I'm locking myself in a room. I'm the worst critic in the world. I write something and then I beat myself up. I'm like "Vin, you're retarded, that makes no sense."
My gut feeling about sequels is that they should be premeditated: You should try to write a trilogy first or at least sketch out a trilogy if you have any faith in your film.
I'm not disciplined enough to be a writer consistently. I write when I have to.
The first thing that happens is the cleansing of the former character. I don't think a lot of actors talk about it, but there is usually a process where you essentially purge yourself of the character played prior to the movie. Then you want to think about what the character represents, and you write down all of the elements about this character and then take the time to find some synchronicity and start breathing the character.