I bought a fold up shelf 'thingy' to hang in the bathroom to hold all of our 'stuff'.....had seen on the boards how many people were so glad they had it. But I didn't need to use it because there was lots of room on the shelves on each side of the mirror in the bathroom. It would be very handy though if there are more people sharing your cabin....there was just the two of us.
We were on the Spirit and there was a hairdryer as well as shampoo etc. provided.
Also many people suggest taking a bungee cord to hold the balcony door open.....we didn't take one with us, but our steward gave us a wooden 'stick' which we placed in the top of the door.
One thing I would have done differently is to take a bar
type extension cord. I took a square one that you plug into the outlet on the wall.... it has a number of outlets (6 I think) on it. I figured it would take up less room in my case but I couldn't use it because the wall outlet was too close to the counter, & it wouldn't fit.
We were glad that we took a small wind-up travel clock instead of an electric one.