These are just some things I found to work, please add your own.
1 put a chunk of soap in your customers hand and let them smell it.
2 Tell a story about your product
3 add a contact card with every purchase
4 add a small sample of soap to customers orders. They often come and buy that soap too.
5 Be able to make up a gift basket then and there.
Just some of the tips that have helped to increase my sales.