Language of openness
The open stance has arms and legs not crossed in any way. They may also be moving in various ways.
Arms open
Arms are not crossed and may be animated and moving in synchronization with what is being said or held wide.
Palms are also relaxed and may be quite expressive, for example appearing to hold things and form more detailed shapes. Open hands show that nothing is being concealed.
Legs open
Open legs are not crossed. Often they are parallel. They may even be stretched apart.
The feet are of interest in open legs and may point forward or to the side or at something or someone of interest.
Looking around and at the other person
The head may be directed solely towards the other person or may be looking around. Eye contact is likely to be relaxed and prolonged.
Relaxed clothing
Clothing is likely to hang loosely and actions to loosen clothing may take place, such as removing a jacket and unbuttoning a collar.