Do you guys double track guitars?

Yes. David Prater did this on the first two Fireshouse albums back in the early 90s and they sound incredible. 6 rhythm guitars tracks and tripled solo tracks. He also orchestrated thickly layered drum samples for the first time (as far as I can tell) in rock & metal music. That guy has never gotten the credit he deserves for setting a new standard for modern metal recording. Many of you might laugh because you're not into that style of rock & metal, but do me a favor. Go back and listen to those albums (and Dream Theater's Images & Words) with an objective ear and listen to the insane layering that is on them!

Awesome production. He used many different amps as well, including a fender bassman head.
 
Awesome production. He used many different amps as well, including a fender bassman head.

Yes, there's a Gearslutz thread where Bill Levity (the guitar player) talks about the sessions. He said his hands were so worn out that he insisted on single tracking the solos on the follow up album, but they still had 6 rhythm tracks on that one too and it sound just as killer. If you remove CJ Snare's vocals from those albums, they could almost pass for any modern thrash or hardcore production. I love how heavy they are and hate how so many people passed them off as "cheezy 80s LA sleaze" records which they certainly were the farthest from. That's east coast metal, baby! No cheeze & sleaze there, just great metal! They spent their time being creative in the studio rather than partying all the time. I had the opportunity to recently meet the bass player Perry Richardson and he reminisced on the recording of those two albums. It sounds like they all had a great time doing them and were all happy with the final product. That wasn't the case with Dream Theater, it appears, but I don't care what Mike Portnoy says, Images & Words is and always will be one of the greatest metal productions of all time.
 
I'm surprised how many quad, it's overboard and unnecessary imo most of the time. I just 2 100& L/R, and a nice bass sound
 
Double track everything, quad track some stuff (choruses etc that call for it) and that's usually it. I've quad tracked an entire ep before and though it was cool, it's nothing I found necessary. Only in the parts I mentioned that can be thickened up for effect!