We used to have a 31' TT as well with a bunk end. On one side of the bunk end was a wooden ladder that you could pull out to use. One you pulled it out, there was a space where it was. We would either place a plastic clothes basket there or use a mesh bag. We've also used the top of the unused bunk bed with the plastic clothes basket as well.
With the motorhome we use one of those collapsable containers like you can use for garbage and use it in one of our wardrobe closets. Works great you can get one with the zipper lid if you are concerned about aesthetics.