u should prlly make sure tht it is straight across where u want 2 cut them and make sure u dont cut in2 the pocket other wise its not usable.when ur done u could hem them at the bottom so they dont fray..unless u like the look.
heres sum insrtuctions:
Put a pair of old jeans into a bathtub full of water with the amount of bleach you desire in it. This amount depends on how light or dark you want your cut-offs.
Let the jeans soak for about a half hour to an hour (once again,depends on how much bleach you put in).
Take the jeans out and throw them in the dryer for about one hour. If they're a little damp, don't worry, you can work fine with them.
Use tough scissors to cut off the legs until you get to your desired length.
Fray the bottom edges and around the sides and the front and back pocket openings with scissors or a pocket knife.
Fray the actual fabric up and down fast and hard to get a rough look, using sandpaper.
and tips:
To keep the stringy fray, you may want to freshen them up every now and then by running the knife across the cut-offs.
When you are cutting your jeans down to shorts, be sure to try them on every few cuts! Remember, you can always cut off more, but you can't always add back on easily.
If you get bleach on your skin, wash the area immediately for 15-20 minutes in warm water.