There are many ways to clean your crystals. Here are the ones we recommend.
Water : Run your crystals under running water and visualise any built up negative energy washing away down the sink. Ensure you visualise it turning back into positive as it hits the earth. (Please be mindful that some crystals are water soluble).
Smoke : Pass your crystals through incense or white sage.
Earth : Bury them in mother earth but remember to use a maker to remind you where they are!.
Sea : If you are lucky enough to live close to the ocean, you can wash them in the sea.
Breath : Use your breath and blow positive energy into them.
Keep an Apophyllite crystal amongst your crystals to help keep them free of negative energies.