We used to hang a barracks bag for dirty laundry inside the door of the wardrobe in the kitchen. It worked for a long time. Then we got one of those mesh baskets to hang there (like you might find in a dorm room). For towels, so far there's just the three of us (son is 17 months now) so we just hang them on the towel bar above the toilet. Extras are either above the master bed, or in that little cabinet above the boot box.
When we need more space for hanging towels in the bathroom, I plan to hang something on the bathroom door.
I plan to install a drawer in the dinette seating like IceOnFire above, but just haven't had the time or the need quite yet.
2014 Jay Flight 28 BHBE
2015 RAM 2500 6.4L HEMI, Tradesman 4x4, 3.73
Blue Ox SwayPro (BXW 1503)
Upgraded from an REI internal frame backpack and a Eureka 1/2 dome tent!