Dan Dermer from Higher Fire Clayspace gives a Crystalline Glaze primer that describes and demonstrates all the basic steps you need to add on to the normal pottery making process in order to work with crystalline glazes. You can find the accompanying handout here: https://ovcag.wildapricot.org/resources/Documents/YouTube%20Linked%20Documents/Crystalline%20Glaze%20Class%20Dan%20Dermer.pdf