Be a teenager!
Make a complilation of all your favourite pieces of music, all the special ones that make you smile. While you're doing it, have a good old dance...and while you're at it, make a copy for a friend.

Remember your Best Friend; send them a message or a card, just to let them know how much you appreciate and value the time you spend together.

Play the "Hi!" game. As you're walking down the road, make a point of smiling and saying Hi to everyone you pass. It'll make you feel good- all those lovely endorphins- and, hopefully, everyone else will appreciate it too.