All trailers first begin with a green public disclaimer about a movie to tell if it is PG rated or universal. followed by the message, the media house or the institution/s logo is shown. the log may be shown after some delay or after few seconds of the trailer.
All trailers end with a page giving credits to media houses who participated in the production, marketing and distribution of the film.
And soon the Darkness
After 37 seconds the music immediately changes to quiet but mysterious beats. the background sound is now slow as now we hear the dialogues of the characters in the trailer. from 0:46-1:16 we see and hear what has actually happened and what the movie is about. After 1:16 everything becomes fast paced as we see series of different clips and the non diegetic background music also catches tempo. We also see more variety of camera angle and movements here.
The Mise en scene is also more rich and emphasizing here. for example in this particular shot the protagonist is standing in a particular valley and the camera rolls around her to that she is the only person there in the valley. Here two girls visit a rural part of Argentina and the Mise en scene is emphasized with the ratty police station office, homes made with plank and bridges with narrow spaces. 
Many transition and effects such as fast forward, fade out have been used throughout the movies. small graphically made clips with catchy phrases which gradually turn mysterious and escalate the anticipation of what will happen in this movie. When a stranger calls
The first 9 seconds of this trailer show a slow pan toward a phone with the non diegetic sound of phone statics and then a person answering a call. We see an insert of a woman screaming and lying on the floor. Now in the first few seconds, audience knows the genre of the movie and that the whole movie would be based on phone calls. before 31 seconds we only hear the diegetic sounds of people having conversation, phone ringing and Nightingale. The tension builds up here after 31 seconds when the protagonist gets a mysterious phone call. music starts playing at the background and the volume gradually catches up. on screen we see the protagonist tensed, attending a series of calls form a stranger.
camera movements used here are quite steady with smooth panning however a fast panning shot that goes inside the house is used just before 01:11 minute. Series of shots of the protagonist trying to lock herself inside the house and calling for help are shown until by 01:11 minutes she receives a call from the police that inform her that the mysterious calls are coming from inside the house. From here the tension escalates and the music changes and catches tempo. Now we see different jerky shots of the protagonist trying to run and save herself from the stranger who has shown himself and is now trying to kill her. Different shots of smaller duration are shown now that increase the anticipation. In the last few minutes just before the title appears, a couple of scenes flicker with the non diegetic sound bridge of phone beeping.
The editing is done here in the two shots at the beginning where the shots have been given a black and white surgical type effect. Words and phrases that appear on the screen vary with the mood created. phrases within the time duration off 00:31-01:11 are just fading on to the screen. Texts after 01:11 are appearing with a swoosh like sound effect and are appearing with a different effect. Fade in transition effect is used throughout the trailer between different shots.
The Roommate
The first 53 seconds show the background of the movie; it shows that there is a girl (Sarah) who for her college has moved into a big city and is bonding with her roommate (Rebbecca). We are shown that her roommate is being exceptionally friendly and generous with her. We see the wide angle shots of the scene's and simple high or canted angle shots of few scenes where Rebbecca and Sarah are enjoying their new college life. How ever the music changes after 53 seconds just after sleeping Rebbecca suddenly opens her eyes as if she was pretending to sleep. The R&b music which was playing in the background abruptly changes into a new track which made the scenes look more intense. After 1:15 we hear a thud like sound effect just before hearing dialogue's which stop at 'medication' and after seeing a look of surprise on the protagonist's face. Till here we know that sarah's roommate Rebbecca is on some kind of a medication and she obviously has not being taking that.
We see close-ups, reverse shots and mid shots of the antagonist (Rebbecca) looking uncomfortable and restrained. After a thud, low rumbling background music is played which make things look edgy.
In 0:08 and in 1:25 we hear bell chimes of the tower in their college which may also be in some way related with the antagonist as in 1:25 we see her getting affected by the chimes and by 1:38 a scene of violence caused by Rebbecca is shown with diegetic sounds of screaming and dialogues spoken in a menacing tone. These bell chimes are heard more often and the scenes shown are more gripping and violent. Entirely different shots of short duration are shown here and parallel editing is done. Here we find out that Sarah's roommate is obsessed with her and it greatly upsets her when her roommate associates with people she disapproves of. In the end we see a chase in an empty house between Rebbecca and Sarah. The bell chimes are now louder and faster and just before the title of the movie appears, we hear someone screaming 'stop'.
Throughout the whole movie, fade in effect is shown when shots appear or disappear into a blank screen. Animation and transition on the text has been done like in all other trailers.
