The vinyl-clad wire racks and bins are great for storing towels and sheets since they provide for good air circulation. Stacked racks can be held with plastic electrical ties.
For extra blankets, pillows, sweaters, or any bulky items, use the plastic storage “bags” that have the vacuum attachment in them. Put your items inside the bag, seal it, hook up your vacuum cleaner hose, and suck out the excess air. The bag and contents will seem to collapse to a fraction of the original size. They will expand just fine when you need them.