Think before speaking - This is not something new, but however often we hear it, we forget to apply it. To think before speaking means to show consideration to the other and then we say the right thing, at the right time, in the right way.
Listen with both ears - We should be an active listener by tuning in fully and being present fully with the person and with the moment. If I am not, I listen through one ear and let it out of the other, or I only half listen, which finally creates misunderstandings.