Saw

When looking at the saw trailer, the first act shown is out of context and uses many colour tones to create an effect to the audience and they use an over-the –shoulder shot putting the audience in to the room and making them feel this particular moment.

The trailers are then shown after this scene, use logos and darker backgrounds.

The next act gives us more story into the film, by showing two of the main characters as well as the villain, jigsaw.  The sound is the villains voice, which is very effective because while he doesn’t say much, the deep sound on his voice tells the audience enough they need to know about him,

At about the middle act of the trailer, the music picks up in tempo and begins to get louder in intensity, a common convention of horror trailers. At this point the trailer edits between scenes and various texts describing jigsaw, the words ‘killer’, ‘voyeur’, and ‘psychopath’ are all shown in between scenes from the film with more expository dialogue about the killer over the scenes. Also, it should be noted that the edits between the scenes in the film and the text are not simple cuts but fades to black, again emphasising the eerie atmosphere.

 The scenes from the film being shown are also seemingly far more dramatic moments than before, coinciding with the increasingly dramatic music. Finally,  the title is shown as well as one last voice over from jigsaw reinforcing the premise. 
 his last voice over has the same effect, saying “live or die, make your choice” which again, isn’t a rhetorical question, but it still leaves the same effects, leaving the audience with a choice.