I think with a lot of fresh herbs they are dried first in an oven on grease proof paper. I have frozen curry leaves over a short period but not all herbs will freeze.They turn black and mushy. There is a site that tells you how to dry herbs in the oven.
I have no need I have a massive bay tree in my garden which my mother bought us as a moving in present in 1980. It was a small pot plant then, :-)
Just put them in a paper bag in the back of your ( completely dry) larder. I have had a bag of bayleaves for years next to my jars of spices. They just sit there - they don't go "off"
I just let mine dry. I used to have a 15ft. high bay tree so the question didn't arise. I've just bought an untrimmed bay tree and potted it up so I will always have fresh bay. If you buy a fancy shaped one they are quite expensive; search around and you will find a natural one very, very much cheaper and trim it yourself!