SOUNDTRACK AND EFFECTS
Other than the voice-overs, which we had completed during the filming of our production in the actual scenes, I had to gather sound effects of things like gun-shots or the punching that occurred during the action scenes within the trailer. Some of these sound effects are hard to find, such as gun-shots, so I had to find these sound effects free of use from the internet, this was easily done through a website called freesound.org, a site which holds a variety of sound effects, which are free to download if you signup.
Some sounds however, could be
made through Foley, Foley is the reproduction of everyday sound effects that are added to film, video, and other media in post-production to enhance audio quality. These reproduced sounds can be anything from the swishing of clothing and footsteps to squeaky doors and breaking glass.
After searching for gun shot sounds, a list of soundclips showed up that I could download, all I had to do was choose a suitable one, appropriate for the gun and the sound it makes when it is shot.
EDIT: Following feedback from one of my friends, one of the gunshots that I used was quite high-pitched and squeaky, so I had to replace the sound effect with a gun shot that produced a larger bang, enough to intimidate the audience and exaggerate or amplify the sound of a gun being shot. This makes the shot more dramatic and gives the scene more depth.