HERE ARE SOME TIPS FROM SUE ON GETTING THE BEST RESULTS WITH YOUR CRYSTAL BALL:
Make sure it is a solid crystal ball.
Try to shoot in the shade. If the sun is shining on the ball you will pick up that sun shine all around in the ball.
The main thing to watch for it is the light reflections on the ball. Remember, if you see it so will your camera.
Don’t hold the crystal ball in the sun as it becomes very hot and could burn you!
Focus only on the ball, but pay attention to your background.
The wider open you shoot, and the further way your background, the more bokeh or blur you will have surrounding your ball.
Position your ball with knowing you will have to turn your photo upside down.
The distance between the ball, subject and camera does matter.
Move the ball around until you find the picture you are looking for. If you have a macro lens, use it. But other lenses will work too. I often use a 85mm for these images. Any lens will work, but shooting shooting fairly wide open helps. Since you are shooting through the ball, you do not have to worry about your own reflection on the ball. You will be far enough away that it should not be an issue.