Mastering Series Part 2: Low End Mastering
Sorry for the longer video but I hope it gives a more comprehensive approach to mastering.
LoAir is a nice plugin for creating ultra low harmonics. Although compression generally is to be avoided on a master, occasionally multiband compression can be useful for taming wild basses and piercing high end. To help the playback system, it's best practice to center the bass.
Links:
The Odd Chaps: / the-odd-chaps
Youno: / younomusic
/ themusicyouno
http://younomastering.co.nr