Years ago when I had an herb garden, I planted marigolds around the edge. They were pretty AND helped keep some of the pests away. I don't know if that will help with snails/slugs or not, but it will work for bugs, at least.

Also, I have heard that setting a shallow container of beer nearby will attract snails/slugs and keep them away from plants. If it is deep enough, they will drown, otherwise they won't, so use your own discretion.

Are you on Discord? It's an app where many Steemians gather in various communities to chat with each other. If you are, there is a Homesteading group that might have answers. I'm not in that group, but I have a link to it, if you are interested.