These shirts (I have 3 of them) are perfect to wear under your favorite tees or on their own. They are soft, comfortable and available in different colors. I'm a woman, so I buy men's shirts in a small size. I wear women's size 8 or medium.
Pros
High quality material
Cons
May shrink when washed. If washed and dried incorrectly, there is a risk that the shirt will shrink and no longer fit as desired.