Free sometimes it is your reason for reading a person that makes them hard to read. If your life depends on it assume the worst. Combine the little things you are picking up about them with what your gut is saying and get the heck out. A poker game on the other hand is a little different. You really want to win but it probably won’t cost you your life if you’re wrong just some money. If you are some kind of forward operator in a battle zone yes you will need extensive training to pick up every little nuance but for your average joe just trying to decide friend or foe it doesn’t take much practice.