fire horizontal lasers a few times to make a nice wide tunnel, run through them, use a diamond pick axe to harvest the ores you want.
with fortune 3 i believe it to be best to turn nether diamonds, coal, and redstone into normal stone first with heat lasers.
you would need a lot of quarries to get ore at the rate that i manually dig them.
on smp i have not been lucky enough to find DENSE ORES in Mystcraft, but involving that would be the best way to get ores by far.