well obviously the engineering of your source tones needs to be decent. What I mean is that you don't have to spend a ton of time worrying about minute details in the guitar tone. If your source tone is solid chances are you won't have to do much to the guitars to make them work. There are instances where just panning and balancing of the mics will be all that is needed. If you need to get crazy with how you process your guitar tracks you should rethink your approach at the source.