That are many things we do that are against the etiquette. When you have a bad cough for example, it is well mannered to cover your mouth with your hand.
However, you shouldn’t use your right hand. That is what you shake with when you get to know new people. If you use that hand, you’ll spread your germs to them. A first shake hand is also very important. It is fundamental to keep a good balance between a weak one and a strong one. You don’t want to appear super not energetic but you don’t want to crash the other’s hand as well.
Also, when you meet new people, wait to be introduced. Do not jump into the conversation, wait your turn. If you have a meeting, be on time. It is considered extremely rude to be late.
And when you get to the coffee place you’re meeting at, seat down correctly. If while you’re sitting, you need to go to the bathroom, just say “excuse me” there is no need to explain why you’re leaving and give details. Last but not least, DO NOT point at people… It is extremely rude!! Unless you’re recruiting soldiers for the army, there is no reason to point at people.