I allways had a problem mixing and mastering my tracks.
Maybe i did have no knoledge enough but hard to learn to get a good sound.
Listening to best commercial tracks, my mix and masters where rubbish anyway.
I use AAMS Auto Audio Mastering System for 2 years now and i have learned so much.
I read the Basic Mixing I,II and III (Resources on the site) and have implemented that.
Also i cannot explain here what i have learned, but looking at analysis in AAMS can be helpfull on the mix i am busy.
Frequencies correcting in the mix returning is my thing.
Ok that takes a bit more time, i do not do one button mastering in AAMS.
My tracks and music have improved to the fact that my friends and my band say it is commercial ok.
Before that never happened, AAMS is the best software for this.
Mix and Learn, Master and Learn, improve.
Finally the end master with reference preset, allways comes out perfect this way.
I recommend to anyone! Even the disbelievers, try it its free!