This technique is very fun and teaches you about ISO, aperture and shutter speed (exposure triangle).
- Cut a piece of paper to fit on top of your lens. I used a magazine.
- Fold it in half and cut a small shape. You will have to experiment on shape size.
- Set your aperture to it's largest setting (smallest number, 2.8 for example.
- Place the paper on top of your lens and shoot at lights. Chances are, you'll need a tripod and a slow shutter speed
- I use manual focus, because I feel it's easier to get the shape.