I use varying grits of sandpaper, wire brushes. Depending on what you are doing with it you can brush salted water over it and let dry. This will form a white residue on it that is somewhat sturdy, but won't last if this is a costume piece that will be worn around. That is for more like a static display type deal.
Good leather im making a gambit costume on a modern movie type costume with comic book qualities im having his cowl chest armor done my xtremedesignfx.com great work the over coat is being hand crafted i have actual shin armor as for the pants dark grey denim with real black leather motorcycle chaps i want to age them a bit around the knees along the seams of the pants a little dull battle damage you know?