There's a certain line of thinking that some garments -- like denim jackets, jeans and leather -- just don't look as they should without some degree of distressing. Rather than waiting years or decades for this process to happen naturally, many take to distressing their garments to achieve the look they seek.
Fray the edges of denim articles with a pair of scissors. Open the blades, then run them across the cuffs, sleeves and pocket flaps to remove color and distress the fibers. Repeat this as much as necessary to achieve the look you desire.
Rub acetone on leather items to fade them. Follow up with a contrasting shoe polish on a shoe brush to add faux "soiling" to the item.
Apply the edge-distressing technique to the edges of leather articles, running scissors across the piece. The result is the "hairy" edge commonly associated with old vintage leather items, like watch straps and belts.
Rub 100-grit sandpaper across fabric and leather items to remove coloring, thin the article slightly and roughen the surface. This technique also works on hat bills, making the cap look like your favorite go-to piece for the past 20 years. More pressure yields faster results.