What space saving tricks for tiny apartments can you suggest?

For giggles.

For example:
A bathtub that one can sleep in.
A Murphy bed.
A two in one clothes washer/dryer.
Make use of ceilings for another floor.
Instead of books have audio books and Kindle books.
Have stain resistant fabrics so one can have one or two sets of clothing.
Instead of having a kitchen have all meals take out.
Drink tap water instead of chilling drinks in the refrigerator.