I found this method in a magazine when I was 13 years old.
Get a white plate and place your crystals in the middle.
Spread salt in a circle around your crystals.
Place a few drops of water around the salt.
Leave plate outside or in a window in the light of a full moon to cleanse and charge overnight.
Collect the crystals in the morning.
Remember to assign them a task or set intentions for manifesting.