Technical conventions +

 Camera

Shot types

There are a lot of establishing shots, which is to make the location a character in the narrative. Close ups are used to make characters dominant such as the protagonist and antagonist.

Angles

Low angle is used to portray the antagonist dominance towards other characters.

Movement

There are a lot of movements in thriller films, which can often be seen to be slow at times. Also there would be movements to follow the characters.

Editing 

Pace

When it comes to pace, it can sometimes vary. However, in a thriller the pace would be slow and deliberate. The pace increases during rapid thrill moments.

Technique

There is some form of montage that is used to give the audience the idea of the backstory of film. 

Montage is used mainly from the antagonist perspective.

Transitions

Film cuts are very dominant in a thriller.

Fades would be very frequent during slow scenes.

Sound

Sound effects

Sounds heard by objects

Sound of the city or environment 

Music

High pitched music

Low bass music

Dialogue

Diegetic dialogues 

Accents from different backgrounds 

Voice overs

Not used in films much, used for animated films etc.