Article: In some cases, you may not be sure how to act or react towards another person. By reflecting the other person's facial expression, you will demonstrate that the two of you are on the same page. In the majority of cases, this will go over in a positive light. It's not recommended to mimic the other person if you suspect he is using sarcasm. Even the most kind-hearted person can come off as rude if they don't tend to basics first. This includes taking a shower at least a few times a week and making sure your clothes are freshly laundered. If you carry a sour body odour with you wherever you go, you're not likely to make any friends and people are bound to be repulsed. Something this simple can mean a world of difference as far as politeness is concerned. Some people tend to blink rapidly when they're under stress. If noticed, this can give the other person the impression that you're uncomfortable or feel rushed. Because this is an involuntary action, it can be hard to train yourself out of it, or even know if you do it. The next time you're in a somewhat stressful situation, try to be conscious of your blinking. This and other facets of negative body language can be eased by allowing yourself to relax. Body language is most often done without thinking. If we are stressed, it is often seen in the way we position our bodies. Even if we're otherwise making an issue to be as polite as possible, this rudeness can manage to get through. The best way to keep it under control is to make an emphasized point of paying attention to your own body language. Crossed arms and an aggressive stance can come across naturally, but if you fix your focus on the way your body's reacting, you'll be able to keep these signs of stress from showing.

What is a summary?
Mimic the other person's facial expression. Stay up to date with hygiene. Keep your blinking under control. Be extra aware of body language when you're under stress.