Recording 2 guitar tracks ?

I have a Line 6 head with two XLR outs I can assign to different models. I set it up so that I have two different clean signals outputting and record both with a different but similar VST amp sim setting for each track and pan them. Seems to work splendidly. Not sure if it's appropriate but I like it. Also I think even if you clone a single identical track you can avoid the problems associated with that method by nudging one slightly forward. When I used to use the clone method though without a nudge (before I knew better) I always set my sims differently anyway and that, although not great, seemed to work okay. You kind of have to use the same performance for lead tracks if you intend to pan them or you are a guitar playing robot.
 
Just my thoughts on the matter... but I'm still learning.
 
;-)

I've recorded two tracks at the same time using two different mics.  To tell the truth, that works ok if you just want to blend the two tracks for tonal reasons and then pan them BOTH in the same direction.  After that, I record another set of tracks and do the same thing except I pan in the opposite direction.  The differences in the two separate recordings (performances) helps to isolate the tracks left and right for a wider stereo field.

Thanks guys, I am using the Axe Fx 2 5153 Red preset and it kicks.

It depends when you're looking for - yes, you can record both tracks at the same time as people have outlined above, but they'll sound exactly the same - if you use different sounds, that certainly helps mix it up a bit. 
 
If you use the method described above to nudge one track over a bit, so there's just slightly different from eachother, that will fatten things up a bit more.
 
I personally prefer to actually recording the tracks separately - the subtle nuances in recording it a second time will distinguish it from the first guitar track and make it sound the most natural and biggest (IMO).
Russ
 

I always record as many tracks as I want in separate passes.
It's quite common for me to use completely different setups for each pass - different guitar/amp/pickups/settings/Fx/mics/pre-amps etc
 
Anything to get a different flavour, but the key is to introduce subtle timing/pitch discrepancies as this is what fattens up multiple tracks
 
I've never had much luck at all with the "clone & nudge" strategy, it just makes it louder and doesn't introduce those little variables you get from recording multiple take

Sidroe
Another secret is to copy the original track to a new one. Then slightly shift the entire new clip just milliseconds out of time with the original. If you shift it too far it will sound like a digital delay. Shift it just enough to hear the difference between the two while panning hard left and right. If you want a different texture use the EQ. This technique makes for rock solid syncing of the performance on the two tracks. Quite often you will not get EXACTLY the same performance by manually doubling the track. But that is sometimes what you want. The little discrepancies make for a more live feel. 

Tony Banks, the keyboard player for Genesis, uses this technique for his keyboards.  I believe the widening threshold is something like 15 milliseconds or less.
 
I am a keyboard player that plays some guitar, and am currently experimenting with splitting an electric guitar signal so that one signal path goes into a direct box, then the 1/4" output from the direct box is fed to a guitar amp, and its line-out is fed to a line-level input on my audio interface, while the XLR output from the direct box is fed to a tube pre-amp - who's output is then sent to another line-level input on the interface.  
 
For the above, both signals will be independently tracked, with two separate instances of modeling and effects, additionally allowing the addition the widening technique to really get a rich wide sound.
 
Hope it works, it's on my to do list for today.
 
Bob Bone