Here are some inputs on body language that would be of great help in our day-to-day life, personally and professionally.

What you say is important, but, What you do is very very important. It has been researched that your body does not lie. Most commonly used body gestures and their meaning. I believe they would be of immense help :-

Arms crossed over chest - Defensiveness or anxiety
Swinging arm - Want to walk away from a situation
Eye blinking - Fast blinking signals stress
Downward gaze - Feeling defeated
Taking notes - Shows interest or involvement
Hand over mouth - Can mean boredom
Arms behind head and leaning back - Looking for power or control
Unbuttoning coat - Openness
Buttoning coat - Feels trapped and wants to leave
Standing with hands behind back - Confidence
Clearing throat - Nervousness
Rubbing back of neck - Defensiveness
Hands flat on table - Ready to agree
Stroking chin - Evaluating or thinking
Foot tapping - Impatience
Rubbing the eye - Doubt or disbelief
Rubbing hands - Anticipation
Tilted head - Interest
Pulling / tugging ear - Indecision

So next time you are communicating, be aware of your's and the other person's body language and understand what it means.