Supplies:

~a magic wand (could use a pencil instead) that is taller than the bottle (when you drop the wand into the bottle, part of it should still be sticking up through the opening.~a bottle that has an opening large enough to fit the wand in (but not too big). The bottle cannot be see-through ~an eraser
If you don't have a bottle that is dark, you can put some dark paint inside the bottle and shake it around so the inside is painted.
Cut a piece off the eraser, just large enough to wedge the wand into the opening of the bottle. The eraser is what makes the trick work!