First off, Why do you even need to cleanse your crystals at all you might ask... Well, when you use crystals and stones especially on a regular basis they can become "clogged" with energy. They get a buildup of excess energy that needs to be cleared away so the crystal may start functioning at it full potential again.
This buildup can come from thoughts, emotions, touching or even just being in the vicinity of objects and people with strong energy fields. There are too many ways to mention all here, but basically everything your crystal comes in contact with will leave behind a bit of it's energetic imprint; Crystals are very impressionable, that's part of the reason we use them, so a bit of regular maintenance will keep them (and by proxy you) healthy and whole!
Cleansing your Stones should never be something you feel you "Have to do", instead do it at a time when you can devote a large amount of love to them, cleansing them is a small way to say Thank You for all the help they offer. It also restores their natural vibrations which in turn makes for happier stones. There is no right or wrong way to clean a crystal only your way, and you may find that different crystals request different treatment. Usually when I cleanse my stones I end up using a combination of at least 3 of the methods mentioned in this blog, however the stones in my personal collection are all heavily used (and I love them very much for putting up with me).
It should be mentioned that certian types of stones are self cleansing, usually these are the types of stone that will by nature cleanse an area (like Kyanite) or transmute negative energy to positive(like Citrine). Thats not to say that they will never need to be cleansed, but usually unless they feel sluggish or tainted from extreme use they should be just fine.
I would love to hear about any other methods you may know of, feel free to comment and share your thoughts, experiences and knowledge!