Balancing after Gain Staging

There's a few ways to skin this cat.
you can leave everything at unity, then lower the gain knobs on your track strips to make sure your master bus is reading between -3 to -6db (that's what you want before master).
 
or you can do what I do, use the summing method.
Each track adds an additional 3db per track. This means that if you have 1 track at 0db then your master bus sum will be 0db. but each track you add at 0db will increase your MB sum by 3db. thus you'll have to make adjustments to lower all your tracks to avoid overloading the MB.
 
in large projects, most of my tracks are as low as -22db. this is because of the summing/ adding 3db per track I mentioned. So I use the gain knobs to avoid overloading VST's that have shallow / no input signal control.
I don't use the gain knobs to gain stage. I have tried it in the past, I just don't hear difference unless of course it is overloading a plug in and sounds like junk. distorted guitar Sims (IMO) seem to sound better with a hotter signal,
even though you can theoretically control this using the input stage on the GS VST, I still find feeding it hot at 0 Gain sounds better than using the gain knob to set up for unity.
Typical project in my studio:
 View post on imgur.com

so in a nut shell... there ya go.
 
 
 
 

for 'riding' the faders having them all at 0 is ideal/easy (if your faders are way down, the increaments change iic and become another factor/calculation to think of when you move them).
personally would leave faders at 0 (if no tracks are clipping) and then adjust the input gain of the bus.
there's quite a few ways/opinions people have for gain staging..

Before I start mixing I lower all tracks to inf. Then I bring up one at a time. Where the fader falls is up to that track. 
 
Chuck has a very well thought out method. Its a good one.