Somebody once wrote that every time you make eye contact with another person you should smile.
I've been doing that for a while now. And nearly every time the other person smiles back. Even on a short walk to the supermarket or the bank, I exchange smiles with a dozen or so people - young people, old people, pretty young girls, macho guys on mountain bikes, little kids - all sorts.
It makes me happy to receive these smiles.
And I hope my smiles give some happiness back.