To start making the baby sign for laugh, take both of your hands and extend your fists' index fingers to make 'L' signs. Point your index fingers at the sides of your cheek, then spiral your fingers upward and away from your mouth as you smile.
Make the laugh sign as your baby breaks into a big belly laugh.
Having the ability to express and identify emotions is key to the development of your baby. Teach laugh during play or when tickling your little one.