It's really a VERY deep question, because not only does it pertain to the patches themselves, and how you play them, but it also pertains to orchestration, and how you use that (and play it!)...

It's basically a 'How do I play music?' kind of question. Without much info on how do you play WHAT?

I suggest you break this down into smaller bites. 'How do I get a better piano/string layer?' or 'How do I use brass patches?' or 'How do you easily voice extensions?' and so on. As it's worded, I wouldn't know how to even START to answer your question...