You can get a sphere on Amazon for about $10-$16. They’re a lot of fun to experiment with to get some cool effects. Here are some things to try: 1. Keep the ball eye level to get the best effect. You can lay it on a flat surface, like the sand, or hold it (or have a friend hold it). 2. Play around with your depth of field to get either what’s in the ball in focus or what’s in the background in focus. 3. They come in different sizes, so if you get a chance to try out a bigger vs smaller one, it’s neat to see how the effects vary. 4.) Try it out with different lenses on your camera too. A long lens is going to show different effects than a shorter lens. 5. Have fun and don’t get discouraged if you struggle at first!