Mason jars are useful in organizing anything. They also can be used for such things as DIY chandeliers, DIY vases, and so on. Storing spices in them is also a great idea. They are capable to hold large quantities of spices and aren’t expensive. They are also easy to stack and refill. If your spice rack is large enough to hold enough Mason jars then they are great choice for you.
Sources: stylelushblog, thekitchn, fallcreekcottage, therigneys, wisdomofthemoon.