Mastering music/final mixes

[Yatsufusa]

Does anyone here produce/remix music as well as master it?
I've recently been practicing the process of mastering on a few random tracks with a ton of dynamic range to get it looking something like this without it sounding horribly distorted, with less than stellar results.

Here's a track I've most recently mastered: 人の夫. It doesn't sound very clean since It's pretty much compressed to hell and back, but it is the best I've managed to do so far. [Visual rep.]
It's a marginal improvement over my first few attempts, but I still know that it's nowhere near as good as it could be in comparison to other songs I've heard that are loud as fuck, but sound surprisingly clean despite some having a waveform that looks like an almost perfect rectangle.

Anyway, feel free to criticize my lame mastering attempt of an otherwise bangin' track. if you have any knowledge on the subject of mixing and/or mastering, some input would be appreciated.