Between the wall studs storage.
Bathroom Storage Solutions - While remodeling this St. Louis bathroom, we incorporated a few storage ideas that could be especially useful in a smaller bathroom
Two towel rods on the back of the door
linen closet with removable hamper for aristokraft - Google Search
Bathroom with shelves for towels - feels like a spa! If we can't add a tub to second guest bath, would love to make the shower smaller and add shelves like this.
For our Home / Small bathroom makeover...
Small bathroom storage idea - By-the-sink shelving using IKEA RIBBA picture ledges.
spa inspired bathroom makeover, bathroom ideas CEILING TO FLOOR SHOWER CURTAIN MAKES THE ROOM APPEAR LARGER; ELEGANT