I still come back from each trip with a "to do" list (will that ever change?!). Something I've always meant to rig up was some form of curtain over the companionway opening. At the jetty I'm now using a de-humidifier (or in winter a fan heater) and it's a fag to keep putting the washboards in place. It also will provide some privacy when needed. I bought a rather expensive one from Force 4 - it is weighted around the edges and has a mesh window which can be opened or sort of closed (could have done without that). I shortened it and fitted some of those turn-buckle type fastenings to allow it to be attached to the sliding hatch.
(note added later): It seems to work well, although I'm not sure how long it will last. It's useful while sailing for stopping rain going into the cabin either when the spray hood is down, or when the wind is from aft. However I need to put a cover over the mosquito net "window" since rain runs off the curtain and into the cabin through that.