Supernatural: The main recommendation to treat Black Death was to confess your sins, and ask God for forgiveness through prayer. If they got the disease, it would be Gods will and if it was his will that patient would die, there was no cure that would work.
Natural: To begin with physicians tried bleeding and purging - the same things they would usually do to correct a humoural imbalance. They didn't work and they seemed to make people die more quickly. Physicians recommended strong - smelling herbs like aloe and myrrh, which were believed to have cleansing properties. Lighting a fire and boiling vinegar could also drive off the bad air. Physicians or surgeons sometimes lanced the buboes - occasionally, people whose buboes burst survived.
Common beliefs: Holding strong Christian beliefs, confessions, prayer and traditional cures like bleeding. Apothecaries sold remedies and herbs that were mixed at home but were unpredictable.