What are the conventions of film openings?

These are the necessities to make a good film opening:

Introduction of the film name

usually with effective and relevant font and graphics.

Establishing shot

these immediately bring the audience into the scene by setting the time and place. These can also set the atmosphere of the film straight away. An example of this is in the beginning of The Shining where we are immediately shown the mountains where the story takes place.

Credits/names and production/distribution company

These are used to credit the actors/directors/producers  and other most important members in the production of the film, as well as the companies that funded the creation of it. (The others are usually stated in the ending credits.) Usually, like the title, in effective font or graphics.

Introduction of main characters

through a shot that immediately allows the audience to become familiar with him/her. An example of this is in The Shining where a steadicam follows the little boy innocently riding his tricycle down the corridors. Just throw this shot the audience can see that he is just a normal, naive little boy.

Acting that hooks the audience

The opening sequence in a film must immediately draw in the audience otherwise they will lose interest in the story before it has even fully began. For example, in Psycho, the story begins with an affair between a woman and a married man. During the 60s, when this film was released, this would have been seen as very scandalous and would have straight away shocked the audience.