You know, not too long ago I was thinking of asking the same questions...but then, I decided to just use my ear
Practice and you will understand
If someone says...oh reso=this and high pass filter that...or something its sort of missing the point...you should search to create these sounds yourself or you may as well just hire an engineer
I guarantee if you sit at your puter 4 hours a day for a few months you can have some of these full on sounds you speak of
just as you can begin playing beethoven songs on piano if you practice
sorry, hope this helps a little...