How to tell if a woman has high testosterone?

A woman with high testosterone will usually have a mesomorph body type. Her body will have a clear hourglass shape, she won't have slim limbs and she won't be obese as well.

A woman with a high level of testosterone will usually be able to develop muscles more easily than her peers. 

Personality is usually subject to many factors and not just genetics, but generally a woman with high testosterone will be more dominant than her peers if she developed normally. 

Woman with higher levels of testosterone usually experience higher levels of sex drive and think about sex more often. (See Why Sex is Addictive?)

While not all humans with high testosterone lose hair, there are some people who are sensitive to a bi-product of testosterone that results in hair loss.

Women with higher levels of testosterone might be more prone to developing acne.

Women with higher levels of testosterone might experience hair growth in many areas of the body such as abdomen, chest, face and upper lip.

Women with higher levels of testosterone might experience more anger and aggression than her peers. Both traits can also be caused by other environmental factors. 

Women with higher levels of testosterone might develop a deep voice. The woman's voice won't resemble a man but she will have a deeper voice than her peers. (See How to have a deep voice?)

Women with higher levels of testosterone might take more risks and engage in more thrilling activities. This might or might not happen depending on other environmental factors affecting the woman.

Women with higher levels of testosterone usually have oily skin.

Women with high levels of testosterone might develop an enlarged clitoris.