After a crystal has been cleansed, it is time to recharge it with fresh energy so you can program new goals and intentions into it. Leave in sunlight, moonlight, or use the vast power within your mind/body/soul to charge to it's fullest capacity.
Use the energy emitting from your own ethereal body, use the sun.
Moonlight charging is my personal favorite. The best time to charge a crystal by moonlight is on a full moon. But depending on if your doing specific moon phase work, it may actually be more beneficial to perhaps charge during a First Quarter Moon (Action).