There are some frayed styles, however, that require a steadier hand, sharper eye and dedicated time like this uneven frayed hem from Mother Denim. In cases like this it's often best to leave it to the experts lest you ruin several pairs of good jeans trying to get it right. 

If you want to break away from a basic frayed hem and try something a little different, this cropped, uneven fray from Mother is a good place to start.