Many musicians who use a software DAW will master the tracks using the same old 2-track mastering techniques like in the old days. I have always wondered why you would ever do that. Why limit, compress and EQ the 2-track stereobus while you can fix the whole mix more precisely?
In short: I never master, I put all effort in making sure my mix sounds great. And if that means I need to make sub groups for beats and compress that, sure I do that all the time. But applying some mastering to the stereobus only? Not my idea of having control over sound.
There’s no need for me to master things, only for mixing it to sound right. I make sure that everything is balanced nicely. And I make sure that I leave about 1 dB of overhead for mp3 and other lossy compression algorithms.
When mixing I compare the track I am working on to other reference tracks. Some of my own and some by other artists. I use both reference speakers as well as the speakers of my MacBook Pro while mixing, because people will mostly listen to it under far from perfect circumstances.
Back in ’66 modernist composer Edgard Varèse said:
What is music but organised noises?
Organised by mixing as we know by now.