Another good way to get good separation when you're layering guitar tracks is to use different chord inversions on your doubled rhythm guitars.
 
In fact, it makes sense to vary as much as you can for your doubles - different guitars/amps/cabs/settings/Fx but the key is still to play them all as tight as you possibly can

I've just started rewatching the Anderton X1 Advanced vids and in the first one he shows how to use the VC64 Vintage channel to to give stereo separation on a mono track without cloning. The gist is you use the both of the VC64's EQs and set the four freq bands to specific frequencies (if anyone is interested I can rewatch and type up the exact settings). Then he turns the gain for each frequency up by 9db on one channel and down by 9db on the other. Pretty cool. Also I now understand what the heck that Vintage Channel thing is. I thought it was just some kind of compressor but now I see it's more of a board channel with all the fancy old controls... which makes more sense considering the name Vintage CHANNEL. lol

The sad thing about Vintage Channel is the product is from a company that has gone out of business. It is stuck at 32bit and may have no future in SONAR.

That is unfortunate. Still seems to work though but I have noticed it can be quirky. Maybe Ckae should try coming up with their own version of it because it is quite nice. Looks cool too.

They did it is called ProChannel

hmm... but it doesn't "split" the signal like the VC does... or can that be achieved with some fancy mucking about?

Either way I'm not sure I'd go about things that way but might try it just for kicks and figured it was relevant to the thread. Cheers.
 

Some great feedback and perspectives - thanks for the replies.  Despite reading about it a few times, I've never used the Haas approach, or other similar approaches of cloning / offsetting multiple guitars on each side of the stereo spectrum, as things tend to sound pretty full with a left guitar panned (either 75% or more) and a simialr one panned right and leads much more aligned towards the center.  As others have mentioned, I typically vary guitar sounds between L and R - e.g. a Les Paul through a Marshall Jubilee on one side and a Strat or Tele through my Marshall Vintage Modern on the right using a different mic on the cab, etc. 
 
But as others have said, it all depends on what you're going for - the 'wall of sound' approach works great for heavier styles. 
Thanks again.
Russ
 

You could try it using 2 sends from your mono track into 2 busses.
Set the Output of your track to "None" so the only thing being processed are your 2 sends.

Probably easier to just pan at that point but perhaps it would add something extra. I think I'm just looking for excuses to use that plug. It looks so freaking cool. ;-)