Hi Greg,
I grow mine as D. cistiflora, and one of them (I think there are now two in the pot) has flowered for the past 3-4 years. They like a very sandy mix (5 parts sand to 1 part peat), and try to give them a large pot as this will help ensure that they don't dessicate in the summer months. Over the summer dormant period they receive periodic watering, just to maintain a bit of moisture in the base of the pot, but never enough to wet the compost through completely. I may only do this every 4-6 weeks (if I remember!)
When they show signs of life (mine are just moving now) I stand them in water for their growing season. They seem to appreciate as much light as possible, and mine are usually under a 400w metal halide light which I managed to smash the other week, so I've decided to see how they and my other winter growers do without the extra light. Having said that, my new greenhouse receives the winter sun, which at my old place it didn't so they will hopefully still perform okay. When they die back I remove them from the water and let them start to dry out for the summer.
Good luck, as it's a spectacular plant. Which colour flower do your plants have, or do you not know yet?!
N