Are you talking about some minor surface scuffs or scratches/gouges?
For very fine abrasions, there are synthetic pads, like Scotch-brite pads,
made to be used in place of fine steel wool. I've had good luck with
some i picked up at Canadian Tire. You may be able to find some
at Home Depot or other hardware stores.
Edit:
Whatever you use, go gently. As you've discovered, aluminum is
very easy to abrade.