Please give a smile it costs nothing

It takes less muscles to smile than to frown.

It is something that blesses both the giver and the receiver (Have you read The Merchant In Venice?)

There is no cost in giving a smile.

A smile might save somebody's day.

Smile makes the ugly beautiful. (Though you must improve looks anyway. Be more handsome.)

Smile is like oxygen for a suffocated person.

Moral: Give smiles, you might get some back. If you don't still smile, It is a win-win.

Cheers, :).