I used Sony Vegas to make this. One of the techniques I used was layering of multiple audio files in a timeline. This technique can be used in almost any video editor I believe. What I did was have one layer of music playing throughout the whole video. On top of that I had another layer or two with snippets from another audio as can be seen in the screenshot below (highlighted in pink):

For example, when something intense is going on in the footage, I’d layer some dramatic music to blend on top of the underlying music, such as percussion instruments. It all adds to the dramatic effect of the video. A screenshot of this is below (highlighted in pink):

Having that underlying music and fade in and fade out effects of the audio files on top, it blends in the audio very nicely. Another thing you can do is slightly decrease the volume of the underlying audio when you overlay a section of audio on top and turn it back up after the overlying audio is done – works well if you blend this shift of volume.

Most of the other effects seen on the video are presets within Sony Vegas. Effects such as saturation adjustments, film grain, and other film effects including jitter, flicker, and hairs to give it the vintage look. This can be seen in the below screenshot highlighted in red. Another thing in Sony Vegas you can take advantage of is when during the video the effect appears or disappears, and this can be done by adding keystrokes to the effect timeline (highlighted in purple in screenshot):

That concludes the tutorial. Hope you learned some new tricks in Sony Vegas and in video editing in general.