Page length is determined by genre. For the most part a rule of thumb
is to have no less than 90 pages and no more than 110. Any longer or
any shorter page length, and the writer is immediately in trouble with the reader.

Formatting is most vital. Cole & Haag’s “The Complete Guide To Standard
Script Formats – Part I: The Screenplay” is the standard by which the film
industry follows.

All camera angles, camera anything, should be avoided in the writing of
spec scripts. Spec scripts are scripts written by writers in hopes of selling
and/or getting it optioned. Writing camera angles in spec scripts shows
writers to be amateurish since camera angles are written into shooting
scripts. Shooting scripts are usually written from spec scripts and the
director is usually directly involved with the screenwriter in writing the
shooting script. Directors know what camera angles they want.
Screenwriters do not because they are not directing the film.

Getting produced usually helps the screenwriter become more liberal in following
these rules. Until then, screenwriters should use a grain of caution in how
liberal they are when writing their screenplays.