Don't have character names start with the same letter, rhyme, or be similar size. (ex. Joe/Jim or Joey/Zoey or Heaven/Nevaeh)
If writing a comedy, tell a good story before packing in jokes.
If writing a drama, tell a good story before writing in the tear-jerking scene.
Know why you're writing this story.
Comedy pilots written on spec have most of their value in being a sample submitted, by representation, to studios during staffing season.
Write about your expertise, whether that's a career, location, or personal interest.
Make your story fictional. Realism for the sake of realism doesn't buy much.
Don't direct the actors with parenthesis in the dialogue.
Use "DAY" or "NIGHT" for the slug line. This is for production purposes. You can be more descriptive about the sun setting or rising or whatever in the action lines.
Don't use ellipsis.
Use action language/voice. Find ways to work around "is."
If writing on spec, don't go above 120 pages. 105-110 pages is sweet.
Directors don't have to follow any screenwriting rules.
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