One way to fatten up a guitar sound and make it sound larger than life is to record one guitar track and pan it hard right or left. Then, if possible duplicate the track and pan it hard left. Here's the trick: the two guitars won't sound special like this, to make the listener percieve more sound coming from the speakers you have to differentiate the two guitars:
1. Delay one guitar by about 20ms. The key is to only let the delayed sound through, just the same track but 20 or so ms behind.
2. Use different eq, sparce effects on one/both of the tracks.
A lot of times people will double track guitars by recording the same part twice, but persoanlly I don't like doing that if there is only one guiatr player in a band, it sounds to busy or fake. The above delay method still sounds like one guiatr player, just with a big sound.
Experimentation is the key...
Ian