I'm growing under lights in my basement. It's not insulated, so it's difficult sometimes to control the temperature, but I try to keep it above 12C in the winter and below 24C in the summer. There's not much variation during the day.
I grow them in NZ sphagnum in plastic pots and keep them very wet. I think water quality and quantity is the most important factor. I use tap water filtered through a Brita filter and flush them out twice a week. When I'm finished spraying them there will be an inch of water in the bottom of the tray, which I dump out. I don't let them sit in water. I don't fertilize them. There is a small fan about 4 feet away which runs 24 hours a day.