If you wonder how to get a shower and a tub in a very small space, note this example. Placing the sink at the end of the tub and the toilet next to it makes things compact. Niches above the toilet and the use of mosaic tile outside of the shower add subtle contrast and keep everything waterproof — a good idea in tight baths.
Put a shelf above your bathroom door to store bulky items like towels. Very good idea for those horrible bathrooms with no closet or cabinets. It should be against the law to build a bathroom without storage!