When I pull in and have sewer hookup and if I have a almost full black tank then I'll dump right then. I like the black tank to have been moving around and it helps to dump before every thing has a chance to settle back down. Our roads anymore make a great stirrer because they are so rough. I also have a tornado flusher and it gets used right after I dump. I have a Rhino hose with a clear section so I can see when the tank is clean (I know what some people won't watch for entertainment :() but it helps make sure the tank is cleaned out. I also use the gray tank contents to flush out the hose.
Most of the time When I pull into a full hookup park I'll need to dump as I most likely have been camping without full hookups for a number of days.