To begin, Find a pair of old, high wasted jeans. Mine are from the thrift store
Measure out how high you want your shorts to be. I drew on my jeans with a washable marker (if you do this, be sure to use a washable marker just in case you mess up)
Next cut your jeans. I cut mine slanted downwards.
Fold the cut pant leg over the other and cut to make sure that they are the same length.
Next cut out a piece of cardboard.
Slip the cardboard under the pant leg and find a cardboard box cutter
Begin to cut slits into the jeans where you want holes. Rub your knife up and down, back and forth, almost like your digging into the jeans to fray them.
Next if you want the ends frayed, rub the knife back and forth on the edge of the shorts. Do not fray your shorts to much because after you've worn and washed them, they will fray out even more.
And your done! Go try them out for yourself! (This is the shorts that I just made so they are not very frayed yet)