In the world of post production audio engineering and mixing, no matter how good your tools are your ears will never be Superman precise. SPECTRAL AUDIO ANALYSIS. One of the biggest mistakes that producers make in the mastering process is a lack of visual representation of the changes you are making to your music in the mastering process. Almost all DAW’s have spectral analyzers. USE THEM. They are critically important because it allows you to see the changes you are making to your sound, it can help you identify unwanted artifacts, peaks, clips and pops.
It can also help you get a good idea of what your track should look like when weighed against professionally mastered productions. The type of mastering reserved for the heavyweights of the music industry with access to the finest audio engineers and equipment money can buy. Visually compare your track to a commercial release in the same or similar genre.
Programs like Izotope Ozone allow you to take a snapshot of a waveform which can then be used for reference. ALWAYS use your ears to master, but use your eyes like you would a VST plugin.
Visualize your sound!! You would be surprised by what you learn.