A teaser trailer is unlike a typical theatrical trailer, they are usually very short in length lasting between 30–60 seconds and often contain little, if any, actual footage from the film itself. Every so often, it is simply a shortened version of a theatrical trailer. A teaser trailer is usually released long in advance of the actual film. One of the main reasons for the trailer to be called a teaser trailer is because it teases the audience by releasing its teaser trailer one to one and a half years before release of the actual film.
The teaser trailers purpose is less to tell the audience about a film and its content than merely to let them know that the film is coming up in the near future. It also adds to the hype of the upcoming release for the film. A teaser trailer is usually made while the film is still in production or when it is being edited. Sometimes in the teaser trailer they may feature scenes from the film but in an alternate version, so it is different to what it would actually be in the final film. This has been done with many Pixar films.
For my teaser trailer I will follow the codes and conventions by making it last from 30 to 60 seconds. I will most likely use footage which would not actually be from the film to tease the audience.I would also make the the teaser trailer a bit silly to make it tease the audience even more, but make it so they would still want to watch the final film when it comes out.