Dog chewed a hole in the back of the knee on your brand new designer denim? Ugh! Fix this bad habit with some easy solutions...

Work with it! Distress the heck outta your chewed-up jeans. Take them to any guy friends you might have that work with power tools and ask them to have at 'em with a bit sander or some oily chains. You will be happy with your "new" old jeans, and the guys will be happy for a bit of estrogen in the shop for once.
distressed denim: by pratt's @

(Think of the old Levi's 501 ad "Easy" for a bit of inspiration.)

Also, a common suggestion I LOVE... the tights underneath idea - go with fishnets or something girly like tights with a heart-shaped swiss dot patterned on them. 
sheer swiss dot pink tights: urban outfitters