Or better yet, consider placing your work on a frame before you start to stitch. It keeps your canvas cleaner, too. How we hate those creatures. Using herbals smell good but do little to deter an attack. Always put your woolens away clean.
Moths love dirty wool.
If you are going to store them then use a sealed container. Moths love dark undisturbed places. Freezing to kill the eggs only works if you have a -50 degree freezer. A household freezer just isn't cold enough. And, unfortunately, the only thing that will kill the eggs, larva and moths are mothballs.