I am in no way qualified to give professional advice.
This is what works for me.
NEWSFLASH: There is not such thing as writer's block.
5 Minute Brainstorm Challenge:
This challenge will force you to word vomit plot ideas that come straight from the top of your head. Things that you are interested in, things that could work, ideas that need solving.
Most of them will be terrible, but hopefully one or two will be worth revising.
Writing should be forced, the idea of a blank page shining back at you, is only possible if you let it happen. By word vomiting on the page shitty ideas, at least you have something to work on.
SET UP A TIMER. GET IT DONE.
5 minutes, 5 ideas
The 2 Page Muscle Stretch:
For screenwriters, this one is more interesting, and it may be a little more fun.
Like writing fan-fiction, in this exercise you create a 2 page conversation between two characters you already know. These character's can be from a movie you recently watched, a show you binged, or friends/family members you know.
Since these are characters you already know, you don't have to set up their backstory or relationship. Just have them discuss something.
It could be Lois Lane angry because Superman put his color suit into the washer, where whites were being cleaned. It could be your best friend discussing why a certain football team is better than the other.
Something to get you in the groove of writing, before you continue working on your award-winning screenplay.
Don't worry about the scene descriptions, grammar, or spelling.
Just let the words spill out of you.
10 minutes, 2 pages