If you have the time, I'd recomend ( along with everything noticing... wrote) working with three or more guitars. Not just because of reformed Maiden, I had a band with three guitars 9-10 years ago and it allows things like obvious three-part harmony, for example with 3rds and 5ths, have two guitars play in harmony and third playing with feedback, do feedback in harmony,just beef up the riffs or anything you come up with. Some of these things you can do on two guitars so try them out. Try various intervals (chromatic runs in a half-tone interval). Try polyphonic melody with different lines one over another. If the people you play with keep solid beat, it should be in sync and sound impressive no matter what you play.