Generally Rude Body Language
There are many gestures that are regarded as rude by most people, or that you are avoiding to interact with them. This includes crossing the arms across the chest, holding objects such as books and a bag in front of you, inspecting the time on your watch or the clock, stroking your chin, standing too close, staring or narrowing your eyes, forcing smiles, placing the hand on the waist, slouching, touching your face frequently, blinking more than usual, foot tapping, and many more. Most of these gestures are done unconsciously, but nonetheless, the people who you are talking to may be offended by the said actions.
Posture And Body Movements
One who maintains a good posture is one who relaxes into the chair provided for him, yet his back remains straight with his chin slightly held up and shoulder pulled back. Confidence is also shown in eye contact and in a firm handshake. A poor posture is shown by slouching; it usually means laziness or lack of interest.
If you have a posture that shows confidence, people will treat you differently. They will treat you with more respect.
Be Conscious Of Your Actions
Be aware of how your body move or act. You might be already sending signals of rudeness even during the moments you do not intend to do so. Make sure you maintain a good posture and perform the proper gestures appropriate for the place and time. You might also as well consider the cultural background of the person you are talking to, and adjust to their acceptable behavior and body language.