Disclaimer: May cause disgruntlement in others. Practice with discretion.

Walk around with an umbrella, black rubber boots and a raincoat in all weather.

If you're female, wear a fake goatee. Stroke it thoughtfully during conversations.

Cut two heart shapes out of a piece of pink construction paper. Tape them to the lenses of some glasses, and then put your new love goggles in your pocket (it isn't a good idea to walk around with them on, 'cause you won't be able to see very well). Go find an attractive person. When they aren't looking, don the love goggles and tap them on the shoulder. When they turn around, stare longingly at them with your hands clasped under your chin, and a big grin on your face.

Clothe yourself creatively. Drape a pair of trousers over your shoulders like a scarf or shawl. Wrap a long-sleeved shirt around your waist like a kilt. If you are in possession of a skirt, you can make a nice headdress out of it by putting the waist over your head and securing it there with a hat or headband.

Put a large pair of headphones over your ears, and stick the end of the cord in your mouth. Hum enthusiastically as you walk down the street.

As a variation on that, attach the cord of a game controller to yourself in some way (you can drop it down your shirt, or stick it up under your hat). Act as though you're controlling your every action with it (steering with the directional pad/joystick, waving at people by pressing a sequence of buttons, etc.). If someone takes the controller from you, fall to the ground and twitch.

If someone gives you the finger, say: "Hmmm... looks like you could use a manicure." Offer to paint their nails.

If you drop something, take off your shoe and retrieve the object with your toes. This may take practice. Stick with it!

Buy some of those glue-on plastic googly eyes, and stick a pair to the tips of the first two fingers of one hand. Put on a long-sleeved coat or jacket and go outside. When you meet someone, slowly slide your hand out of your sleeve, and "look" at the person as you talk.

Don a long, black Batman cape. Adopt your best "brooding gargoyle" pose atop a fencepost, and stare implacably at passers-by. Inform the curious that the cape matches the darkness of your soul. (No need to wait for them to ask first.)
- from Riverfox237