As Shantideva said, "There is nothing that doesn't get easier with practice." When you can really laugh from your heart and your gut, everything opens up. Then you won't be like a professional clown: funny for others, but very serious about yourself.
Young girls are very fortunate because they giggle a lot. True giggles, not nervous or self-conscious giggles, are a kind of massage for the heart. They help us touch the joy in our lives. Giggles, laughter and the kind of "ha, ha, ha" that old men make when they laugh with their bellies shaking — they all help us to not take this short life too seriously.
— Dzigar Kongtrul, It's Up to You