Well, I like using potted plants in my enclosures. Granted, I don't have nearly as many snakes as some people so the extra maintenance isn't a big deal.
I just put my plants in ceramic pots and sort of load hides and things around them. Generally I use christmas cactuses, and orchids. Some of the orchids are really nice because they have the same humidity and temp requirements as the snakes, and some of them are epiphytic (grow up in tree branches and on rock cliffs). The epiphytic orchids I can just tie to a log and then mist them once a week. "air plants" would also probably work very well. They are supposed to be really easy, but I always end up killing them somehow.
The snakes seem to enjoy basking on the live plants, and prefer the live ones to the plastic ones. They also seem to help keep the humidity stable and also make the vivs smell better (At least in my opinion)
Do be careful if you get live plants though, some nurseries spray their plants with pesticides and use chemical fertilizers which can harm your snake.