After the dynamics and tone are taken care of, it’s time to enhance the whole thing. This isn’t a necessary step, but you can take it if you feel it fits.
The first thing to look to is saturation, whether it’s a plugin, a tape emulator, or an exciter. They all basically do the same thing: saturate the sound in order to add color to the mix. It makes the whole track sound fuller and more exciting.
But here’s the thing: it’s easy to overdo saturation. Adding too much saturation can distort the sound and end up making it flatter. Just a touch is all you need.
Another way to enhance your master is by adding stereo widening. It helps everything sound, well, wider. The majority of wideness in a song should be taken care of during the mix, but just a little bit of widening during mastering can go a long way.
On the other hand, widening can also cause phasing issues, making the song sound worse in mono than before. So only use a sprinkle of widening.
The final way to enhance your master during this stage is with volume automation. You can use this to bring out certain parts of the song. You could make the last chorus one dB up from the rest of the song. Not enough that people would be fumbling to turn down the volume, but enough that it would make an impact on the listener.