In an RV, space is at a premium. And no where is that more true than in the bathroom.
There isn't a lot of room there for extras. But we've added two little items that, to me, are great accessories.
The first is a very handy retractable 8-foot long clothesline we found on Amazon for around $16. (http://amzn.to/1WXei4z). We have it mounted along the back of the shower enclosure and we use it to dry towels and the like as we travel.
Something else I added was a magnifying mirror we also found on Amazon for about $25 (http://amzn.to/1QswnmF).
We drilled two small holes in the back of the shower, screwed in the base, and sealed the edges and the screw with a small bead of silicone. The mirror folds up flatagainst the wall when we're traveling and extends out when I need it for makeup application.
Both are inexpensive, but very convenient additions.