You don't have to wear your jeans every day for years to achieve the lived-in look of a comfortable, creased pair of old faithfuls. It's true that clothing manufacturers sell jeans with factory weathering, but these ready-to-wear garments may not look exactly the way you want and can include extra distressing effects -- like holes or worn seams -- that don't tickle your fancy. Add your own wrinkled look to the legs of a new pair of jeans through a variety of scraping and pressing techniques and you'll ease into your perfect pair in a matter of days, not decades.
Put on the jeans and sit in a chair, then rub the sandpaper over the thighs in downward strokes. The fabric crinkles naturally into whiskers and the sandpaper scrapes the design permanently into the denim.
Mark out the desired wrinkle positions with a piece of white chalk and then slide a piece of cardboard or a book inside each leg so that it lies under the chalk markings. Wrap a pencil end with sandpaper and scrape the paper over each of the chalk markings.
Slide one leg of the jeans onto the end of the ironing board and scrunch it once to make a wrinkle. Adjust the wrinkle to the desired shape and iron the crease on a high steam setting to make it permanent. Scrunch the jeans again to make the next wrinkle. Repeat until you have the desired amount of wrinkles in one leg and then repeat the entire step with the other leg of the jeans.