Effective communication is one of the most important skill, so it is important how to communicate and what things are required for it, because A good communication present yourself in a good way.
When you are having a conversation with someone, make an eye contact. Let them fill that you are interested in their talk. When you are explaining something, use your hand gesture to justify it. Don't use Hmm, that's very irritating. Never cross your hand while talking to someone, It indicates that you are not interested in their talks.