Depends on what she is trying to accomplish. Lets face it, ugly extremely ugly guys generally don't even like ugly or even average girls.
BUT I know of one very effective way that even an extremely ugly girl can become attractive to guys they desire. The key is to be as feminine as possible. Be mild mannered, agreeable, uplifting, and playful. Wear dresses and skirts as much as possible. Grow your hair long and wear it down as much as possible.
Looks are very important to guys and good looking girls definitely have an advantage, but femininity is even more important than looks. Things like personality and common interests don't really matter as much as those two things.