Nervous nail biting can be done sometimes without knowing you are even doing it. It shows someone is nervous, stressed, or anxious about something and while it isn’t always a bad thing to be nervous, displaying it in this way is not the most appropriate in a business setting.
Smiling, open, positive body language shows you are approachable while maintaining good levels of eye contact show the other person you are interested in the conversation. Affirmative movements such as smiling, or nodding your head lets other people know you are identifying with what they are saying.
Yawning can be a sign of tiredness, which can come across as rude in certain situations. Avoid is possible and if unavoidable, don’t speak while yawning and always cover your mouth.
Crossed arms, is a physical barrier to other people, it shows you are shut off and not open and thoroughly involved in the conversation, or meeting. A slouched posture can come across to others that you are disinterested, tired or lack confidence.