The Turn LineThis is the part of the trailer where the music drops out and there is dialogue. This is usually the point where the action starts. (Good examples:
This follows the turn line. It lead to the big finale that the trailer builds up to.
Pounding dramatic booms used to punctuate trailers. (Good example: )
This is the scare or joke that comes immediately after the main title reveal. It ends the trailer with a bang.
It is important that the right soundtrack is used, as they are a very important part of the trailer. Some soundtracks are made specifically for the trailer, which makes them fit perfectly with the scenes that are in the trailer. Sometimes, this is not the case.
It is important that the soundtrack effects the person emotionally, as this will mean that they are more likely to go and watch the film. The soundtrack helps to sell the film within the short amount of time that is available in a trailer.
Editing and Camerawork
Shots have become shorter and more fragmented, and each year the average length of a shot decreases. This is because the audience absorbs the information faster. Typically the cuts become quicker near the end, or with the action, and they often go along with the sounds.
There are comparisons with old films, with their trailers being much longer than the trailers of new films and also having less shots and cuts.