Wash crystal gently in water with a little salt. After that rinse them in clean water, and dry. Polishing it with a jewellers cloth if you like your crystals super shiny.
Bonding and Programming Your Crystal
Find a quite place and hold the crystal in both hands, try to feel it with your mind, concentrate on what you want to program into the crystal. This process takes a few minutes.
You can assign your crystals any purpose or desire that you have. The vibration is stored there until you replace it with a new intention.
Source - CrystalPalace