Trailer Components

A very simple structure for a film would be

Start - middle - and end

However your trailer will not give the end away, so you are likely not to include any of the

resolutions but might include final crisis scenes.

Your film opening will obviously be part of the start and should introduce

      main character,
      location,
      genre,
      and maybe give an indication of the everyday normal life of your protagonist.

However the trailer is not in chronological order and need not start at the start.

You can go straight to inciting incident which is where life changes for the protagonist 

and what becomes their crisis.

You should throughout your trailer clearly identify genre,  so not only do you have to know 

the genre but you also need you know the signifiers for that genre and include some of them.

Consider the use of a voice over, narrator or inter titles.

Create a sense of enigma where the audience need to watch the film in order to have

their questions answered.

One criticism of student trailers is that they give too much of the narrative away, DONT.

And another that they are too slow in post - use short shots but lots of them.

Construct your trailer as a separate entity and put shots together that work not 

necessarily following story line.