Not pretty, but cheap and efficient, I use three plastic crates hinged to the bulkhead at the foot of the bed, secured with bolt latches. When open for access (see the one on left) still allow 12 inches clearance for feet.

My daughter has a pop-up and uses the cloth divided closet storage bags hung horizontally from the roof over the sink and bed areas. She uses them for bedding, clothes and light food such a bread, cereal, chips, etc.
This is just and example - she found some that had a full zippered front. They fold flat when not in use or can be carried full in the tow vehicle.

M C