If those brand-new pair of jeans are looking a little too new for your liking, there's a way you can distress them with supplies you probably already have around the house. No need to spend the extra money on "designer distressed" jeans when taking a little sandpaper to the hems can make any pair perfect.
Wash your jeans--especially if they need to be hemmed. Jeans shrink more in the length than in the width, so prewashing is very important.
Hem your jeans. Have a professional mark and hem your jeans to the length you want. At the fitting, be sure to wear the shoes you plan to wear with your jeans. Ask the seamstress to give you any fabric she cuts off--you'll need this to test your distressing technique.
Try distressing a scrap of fabric. Use your sand paper or emery board to distress the cutoff hem or an old pair of jeans. When doing this, think about how jeans wear normally, and try to emulate it. For example, the back hem tends to wear faster than the front or sides.
Run your sandpaper or emery board along the folded edge of the hem to create your desired effect.