You could do well be joining a laughing club.
You could surely find at least one laughing club
if you go out for morning walk in your locality.
Or you could just stand or sit in front of a mirror
and smile or laugh out to yourself for just a few minutes.
Or if you just cannot do all this,
I only suggest one more thing.
And this is one of the most important things
that anybody may have told you about ever.
Never doubt the biggest and largest store
of smiles, laughter, peace, happiness, joy, playfulness,
cheer, joviality, sanctity, euphoria, and content,
that you have always with you in your mind and heart.
You only have to do some regular silent meditation
sitting somewhere, or anywhere with elements of nature,
for up to one hour, and not more than that.