I just passed page 60 on my current screenplay. That is 60 pages in under 2 months. For me, that is a great pace. I find that by telling myself I only have to write ONE PAGE and then I am free to do other non-productive things, like gaming, television or social media, I actually trick myself into writing much more.
I click the Movie Magic Screenplay icon, read back a couple of pages and get going on my supposed ONE PAGE, but I never stop at one page. Once I get myself in the zone, it's so fluid that I can't stop till I have exhausted my brain, which isn't easy to do. One page turns into ten naturally.
Overcoming that first objection by telling myself I am only committing to ONE PAGE seems to work for me. Do you have a trick that works for you?