One more vote for the 5x5 PVC fence post mod. I painted mine black to match the trailer. I am able to store all fittings and several lengths of rain gutter to use as hose support when needed. The gutter doubles as a drawer of sorts for easy access. I use the rear "bumper" for the dedicated black tank flush hoses and a fire poker.
One thing I would like to figure out though, is a convenient place for used disposable gloves. For some reason trash cans and dump stations are rarely, if ever, found together.
'04 GMC Sierra 2500HD, CCSB, D/A, MaxBrake, B&W Companion, Retrax Pro, AR Power Steps
2013 Rockwood 8289WS w/Diamond pkg
1969 Camaro RS/SS Convertible
Dad's old 1968 Empi Imp (recently recovered from under 21 years worth of boxes/dust)