When not boondocking in our truck camper, we usually plug-in and then connect to fresh/black/gray/CableTV as needed or if we're not going to be using the camper for short drives nearby for awhile. When black/gray are connected, I keep the valves CLOSED most of the time. When I dump, I want a rush of water, and in some RV Parks it seems like there is positive air flow out of the sewer system which just fans up the black/gray smells if the valves are left OPEN.
We often use the RV Park's shower since our TC's shower is cramped and I like to keep it dry as much as possible.