In these tutorials Echo Sound Works explains four fundamental techniques to getting that desired balance in your mix. Shows you how to use Mid Side and MidLeftRight processing to clean up muddy mixes.Mid Side processing is a common technique that allows us to split the audio signal into the Mono (or mid content) and then the side (left and right usually). This is especially helpful on synths and instruments that are stereo tracks because you can EQ the middle/mono content independently from the side content. You can take this process a step further and split your stereo tracks into three individual stems or tracks. Make sure the center one is a MONO track and the pan the other two hard left and hard right. This will give you the utmost control over each element in the stereo field.
There are 3 reasons why you would typically want to “layer synths”:
1.) To make the sound BIGGER
2.) To make the sound more interesting and or unique
3.) As a work around for certain limitations with software synthesis.
You should not however, layer synths with the hope of making a bad or mediocre preset sound good. This video also discusses some nice tips and tricks to help make your synth layers fit into a mix a little bit better.