Keep your Crystals free from grime and dust, store them in the correct way and cleanse them energetically regularly. You should cleanse your Crystals before and after using them for your Crystal Net / Pattern.
One of the easiest, quickest and best ways of cleaning your Crystals is by using your intent. In your mind you see the Crystal as being cleansed. This could be visualising holding it under a waterfall or surrounding it with white Light. You can reinforce this visualisation with a physical gesture such as moving your hand over it or blowing on it.
If you do not feel confident doing this then another quick and easy way is by using sound. This is a lovely way to cleanse your Crystals. You can simply clap your hands together to dissipate the stagnant energies surrounding it, or you can use a bell or some cymbals (tingsha bells) to help you do this. Playing beautiful music, such as Gregorian chants or the Ave Maria can also work.
When you cleanse your Crystals in this fashion you also automatically cleanse your own Aura / Energy field and the room you perform this in.
There are many more ways of cleansing your Crystals, so please check for them on the internet or in Crystal books if the above methods have not done the trick.
Our opinion is that EVERY Crystal should be checked to see if it needs cleaning. Yes, some types of Crystals are more resilient than others and are very practised at holding a high vibration, but just like us they can attract undesirable energy.