Trailers Forms and Conventions
Special Effects
This could either be:
Freeze Frame
Slow Motion
Fades
Wipes
Fast Pans
CGI
Movie Information
Captions
Director
Producer
Actor
Release Date
Sound Track
Break With Continuity Filming Principles
In a trailer you are unlikely to see a long shot and instead you would see fast cuts from one scene to another as they don't want to let a lot of scenes out.
Heavy Emphasis on Close Ups
To emphasis the trailer they insert close ups which could either be someone holding a weapon or the back of someones head. This is used as in teaser trailers you are not given a lot of information so the close ups is to show the main shots to make the audience think about whats going to happen.
A Range Of Visual/Camera Styles
IF the film is Paranormal Activities then the visual style would be hand held documentary realism where you would have the characters holding the camera instead of a camera man.
A Focus On Key Character Traits
All characters in a teaser trailers are all important as they could be either the hero, villain or a suspect. The trailer wants to introduce us to a character like Liam Neeson's character in A Walk Among The Tombstones as he tells us about himself.
Fast Cutting
Is used in mostly action shots and suspense moment.
For example in the Expendables trailer you have a lot of action scenes which only stay for a few sceonds and moves straight away to the next one.
Shots
Every shot should be there for a reason in teaser trailers they want you to be aware of who's character is like and what happens.