When in a meeting or while discussing with someone, at the end of the conversation, always repeat what you just listen to. If you are given an instruction to do something, even if you have taken the notes, clarify what you have understood instead of just nodding that yes you got it. And when you have any given an instruction ask to the other person what he has understood.
This way you will make sure that both the parties are on the same page and if there is any misunderstanding in delivering or receiving the message it would get cleared there and then.