Whenever I'm  down, I  try to listen to an imaginary tune  in my mind  (Smile  by Nat King Cole):
Smile though your heart is aching 
Smile even though it's breaking 
When there are clouds in the sky, you'll get by 
If you smile through your fear and sorrow 
Smile and maybe tomorrow 
You'll see the sun come shining through for you...
Many times, there's no other way to be happy  but  to smile,  cheer ourselves up  and  move on.
smile artwork
Life is like a mirror, we get the best results when we smile at it. ~author unknown

A kind heart is a fountain of gladness, making everything in its vicinity freshen into smiles. ~Washington Irving

Peace begins with a smile. ~Mother Teresa