Originally Posted by Xujih

To put it simply, it has nothing to do with gear at all. The difference in quality that you are noticing comes down to three important things. 1) Space: by equalizing and compressing your layers well, removing overlapping frequencies and creating space for frequencies to shine through, you create a clearer layering of sounds. 2) Mixdown: this is the most important part for you - you need to make sure that your peak master volume is at or below -3db and that all of your levels sit nicely with each other, none is too domineering or too quiet in the mix. A good mixdown is what makes for a good master, so if you get your levels right then the third thing, Mastering (3) will be a piece of cake for your master.

Mastering takes your track, makes minor sonic adjustments and increases the volume to the maximum level possible without clipping. This is where an amateur song can be made to sound "professional" as you call it, but realistically a master shouldn't change the sound of the original song dramatically, but instead simply even out its sonic range and increase its overall volume and stereo width. If you as a producer make sure that your mixdowns are good and that you have space for your frequencies to breathe then your masters will be good and your tracks might start to sound better