Balance writing time with "filling the well" (museums, hiking, reading non-fiction).
Carry a notebook. Eavesdrop on conversations for natural dialogue rhythms. The Craft: Structure & Story
Watch and analyze the top 10 movies in the specific genre you are currently writing.
Writing one hour every day is better than writing 10 hours once a month.
Spend 80% of your time on the beat sheet and 20% on the actual script.
Write something—anything—before checking email or social media.
If you can't explain your movie in one sentence, you don't have a story yet.