Due to the house being older, the floor is quite sloped at the outer walls where we put in the bathroom. This meant that the toilet and bathtub had to be shimmed to get them level.
The owners decided on an inexpensive tile for the tub surround, with a fairly expensive but small signature highlight about 2/3 of the way up. Then we installed drywall over the bathtub, making sure the ceiling was as high as possible where the shower head is. The rest of the bathroom has a hanging ceiling so that all the phone, cable, and upstairs plumbing can still be easily accessed in the future.