Go at the right time of year. Picking the right time to visit the Dead Sea is basically an attempt at balancing the extreme heat of the summer months against the large crowds of more temperate times of year. Think about going in late fall, mid-spring and early summer so that neither the heat nor the crowds are overwhelming.
Take a bus or rent a car. One of the best things about the Dead Sea is that it's very easy to get to. Since the sea is only about an hour and a half from Israel's population centers, getting an inexpensive public "Eged" bus or renting a car makes the trip convenient and affordable.
Go to a seaside spa. There are a few different spas on the coast of the Dead Sea that offer easy access to the shore, mud baths, sulfur pools and freshwater showers to clean up afterwards. The Dead Sea Spa is an inexpensive public spa that many tours frequent and provides all the services you might want. Check out one of the hotels, such as the Meridian, for a more exclusive spa.
Use the mud and salt. Along the shore are large concrete buckets of Dead Sea mud, which is quickly becoming a desired commodity on account of its revitalizing properties. Smear yourself in mud and then take a dip in the famous waters where you'll float without having to make any effort.
Check out Ein Gedi and the surrounding area. Ein Gedi is a Dead Sea kibbutz that is famous for its spa, its lush gardens and its fine restaurants. Head to the kibbutz for a meal and to hook up with a tour of one of the many Dead Sea wadis, or oasis-gorges, where cool pools of water lie in the shade of canyon walls and an occasional palm tree.