Use them powerfully, cleanse out what they have taken from your work, and then re-empower them. It is the cycle of a working crystal. Again, there are several ways to power up a crystal. Be sure to follow your intuition. However, no matter the method you use, you will be using your intention to enliven your crystal.
Intention is everything.
Hold the rounded end of your crystal in your right hand, near its base. Hold it out in front of you in a horizontal position, with your left palm outward and turned toward the faceted end. Allow yourself to move into communication with the power emanating off the faceted tip as it points to the palm of your left hand. You will want to feel an increase of the emanation, pulse, tingling or power that you feel on your left palm during this process. Stand with your feet shoulder width or slightly more than shoulder width apart.