What to expect to see in the opening 2 minutes of a feature film? (want to put this at the start of my blog)

In a 2 minute opening important infomation shouldn't be given away. Dependent on the genre, different conventions will be used. For example, in a horror film (using mise-en-scene)the setting of a dark/gloomy environment would be typically used. Sharp/quick shots (3-4 seconds) and not much speech is normally a convention. Normally sound is used instead of dialogue (more non-diegetic) Some that I have seen are very simple and have a music track in the background. The music is relevant to the genre. For example, for a action/thriller fast paced and up beat, maybe rap or R and B. Production idents emerge and occur at the start and sometimes during the 2 minutes.