When I pull up a song into a mastering session I hit play and just listen. Does it need anything? If so, what? Maybe nothing? Maybe it just needs to be louder. I never want to squash the dynamics especially when I know that in my mixes I work hard to get things moving just right. I don’t assume that the mix needs anything but when it does I know it. Maybe it was recorded on really clean, colorless preamps and it really needs a little saturation. Try getting a robot to recognize that in your mix. Maybe the overheads are harsh and the vocals are way too essy. Maybe the bass is super boomy and needs to be cleaned up a little for clarity. How loud is too loud? They say the loudness wars are over. That’s good news for sure if it’s true. The streaming services turn your songs down anyway so in theory you end up with a smaller, more squashed sounding track if you master it too hot. Still, loud and proud works well in some genres so I approach it song by song and do whatever suits that song best while trying to stay competitive. I also A/B to other professional masters in the genre to make sure I’m in the ballpark. I’m not talking shit but I have had mixes completely obliterated before by other mastering engineers. It’s happened more than a few times and that’s why I like to keep our mastering in house whenever possible. We make this worth while by offering super affordable rates to bands that stick with us for mastering.