Hi Samuel,
It is best not to be shackled to the idea that you have to read a woman’s body language first to determine whether she likes you so as to approach her.
Oftentimes, a woman can be closed off with her body language simply because of habit. In other words, she may actually be open to being approached. She just doesn’t have good body language habits.
If you are always looking for positive reinforcement whenever you are trying to read a woman’s body language such as establishing eye contact with her, you will miss out on many women who may not have particularly inviting body language habits but who may still respond to your approach in a positive way.