When you’re in the mood for a new movie, one of the first things you do is watch a trailer. These two minute mini movies are a crucial part of the film making process, and they’re becoming increasingly important as studios embrace the internet for their marketing strategies. Trailers can be a preview of the story, but they can also serve as a teaser for the project, and can build up anticipation with countdowns and special viewing events once the trailer is released.

Historically, movie trailers came before the feature film they were promoting, and they sometimes even included material that did not appear in the film. The earliest trailers, for example, were compiled from rehearsal footage of Broadway shows that were being shown at Marcus Loew’s theaters.

Now that we live in a post-DVD culture, trailers have expanded beyond theatrical releases and into the realm of online distribution. Filmmakers and producers are teasing their projects online in a variety of ways, from splicing teasers into YouTube videos to posting short gifs on Instagram to promote them. The trailer is now a vital part of the filmmaking process, and it can take on a life of its own as it gets shared and discussed across social media.

A good trailer will capture the spirit of the movie and draw the viewer in. This can be done in a number of ways, from the use of music to the way the film is shot and edited. A great example is the Joker trailer, which uses a perfect mix of humor and action to sell the film. It also features a great performance by Jared Leto and an amazing choice of Queen music, which really accentuates the emotion of the scene.

For example, in a film that is about a world-ending disaster, it can be helpful to highlight the threat that is being faced and how dire the situation is. Using dramatic music and shaky cam can also work, as long as the tension is built up and not simply deflated. The biggest mistake in the Battle: Los Angeles trailer, however, is not building up the premise but merely showing lots of action scenes without any narrative context.

A good trailer will have a sense of urgency and a cliffhanger that leaves the audience wanting more. It will also make sure to include a lot of action, which is a must for a genre movie. Finally, it will make sure to set the tone for the film with a compelling story and a great cast. This is how some of the best trailers manage to rise above the rest, unlike this one from Battle: Los Angeles that seems to be about nothing at all. This is a shame, as the filmmakers may have actually made a great movie under these circumstances. This is why it’s so important for movie makers to pay attention to how their trailers are crafted, rather than having them look like they were made by a high schooler in After Effects.