I have so much extra starter, like 3 quart jars full. When I have to remove some starter from my crock at "feeding time", I hate to throw it away, so I would just put it in jars and stick it in the fridge. I would then use it as back up in case something went wrong with my crock, use for giveaways, etc. However, not many people that I know bake bread, so it builds quickly. And the jars are taking up space.
As a result, I have begun to dry the starter, a jar at a time. It is easy to do. (Pictures below, in order of steps.)
I place parchment paper on a platter or cookie sheet. I then spread a thin layer of starter on it, set in an out of the way place (where no dust is flying and little kitty paws can't disturb), and just let it air dry. (Oven or dehydration heat can affect the yeast.) When THROUGHLY dry, I then peel off the paper (which you can reuse) and break into small pieces. You can store in pieces or grind into a powder, which will be what I will do next. Store in dry, airtight jar.
Note that I always make sure that the starter is active before I dry it. So the jar that I am drying the contents of, is kept out of the fridge, and fed once a day (sometimes every other day) until I have dried it all.