1. Analysis of a film trailer
Promote the film:
To promote your film through the film trailer you should include a release date to build hype around the film so more people are counting down the days until your film is released, a title (if it is part of a pre-existing franchise this will cause more excitement for the fans, making more of a buzz), key actors as fans of the actor will want to see the film just for them, making it more popular, a director as they have a unique style that people will be familiar with and a fan of them and include producers for the same reason, reviews to make the film seem good as people will talk about it to their friends and say that it got good reviews, causing it to be popular and a studio name as, similar to the director, they have a unique style that people will be a fan of.
Conventions typically included:
Voiceover (anchors key points)
Sound (to set the mood / genre)
Title (anchors key meanings / promotes franchise)
Cast (Allows audience to decide if appealing to them)
Camerawork & Editing (to make the trailer flow)
Engaging the audience:
Everything that is included should be aimed toward your target audience. This might mean that instead of magazine reviews you include a review from a website like IMDb. This also means that social media should be included at the end of the trailer for viral marketing
Analysis of a film trailer
There are two types of trailers, theatrical and teaser. Theatrical reveals more of the plot whereas a teaser will just show a small part of the film
Dis-equilibrium:
The threat is introduced, the character is harmed in some way be it themselves or another character death, they realise they are supposed to overcome and transform to defeat the threat, this is usually the most climactic part of the trailer.
New Equilibrium:
The peaceful state is restored but usually is different from the beginning of the story, usually a character death has impacted them so they can never return to normal, in a trailer there is only a hint to resolution, it is, of course, not revealed.
Narrative Hints:
In a film trailer, for the film to still seem appealing to the audience you should include narrative hints such as character information, key structure (beginning, middle and end) and the genre.
Equilibrium:
The storyline is established, the character is introduced in their normal day-to-day life. There is no threat here, but can be building to the threat / traveling.

2. There are different types of trailers to help out with the promotion of the film. Firstly, you have a teaser trailer which is usually released first and quite a long time before the actual film is released in cinemas. This is to give the audience a small glance at the film and maybe even not show the title. This is because it gets people talking about what the possible film is, bringing in hype.
An example of a popular teaser trailer that was released recently, ‘Star Wars: the Force Awakens’. Before this trailer was even released there had been a large amount of hype surrounding this film as the rights to them were recently bought by another studio which gave pre-existing fans the idea that a new film was going to be made. This trailer was released almost a year before the actual film was released which is a good promotional method because it leads to a larger audience being gained, giving them time to catch up with the other films.
For example, Marvel actually released a teaser trailer for a trailer the day before it was released. The only hint was the image of the shield from Captain America at the end of the teaser. This kind of trailer would create a huge hype. Here is a link to watch this teaser:
Film Trailers
Furthermore, you can get a full length trailer which is often 4/5 minutes long. In this trailer, some key narrative points are revealed, the key characters and the title. These film trailers are often most popular as it gives the audience an idea of if they want to see the film or not so it is important for the producers to make sure to grab the audience.
For example, this full length trailer for X-men was released after teaser trailers giving it a huge hype and causing there to be a larger backing. Here is a link to the trailer: