You can find great ideas at sites like http://www.call1stchoice.com/remodeling/bathroom-remodeling/ where I found this one. Today everyone loves a large bathroom and you have to have 2 sinks.
Most everyone that is looking to buy a home wants a separate bathtub in the master bathroom. They do not want just a shower anymore or a shower tub combo. If you are building or remodeling I always recommend a separate tub even if you do not take baths. Someday you will be selling the home and it is much easier and cheaper to put it in now. You will get your money back without any trouble.
And you should really consider how much tile you will put in. http://www.rebaththesouth.com/remodeling shows this bath which is done just the way I like it. You should take the tile in the shower up to the ceiling and go half way up the walls all the way around the rest of the bath. I love travertine and so do most people. I would get the largest tiles you can and lay them as close together as possible. The only complaint people have about tiles of any type is cleansing the grout line so that is less of a problem if they are laid close together. And make sure you seal the grout with a really good sealer.
Generally the floor is the only place that gets really dirty, the walls are not that hard to keep up and neither is the counter top. Colored toilets, tubs and sinks are starting to make a comeback so you may want to consider that, of course I don’t think you can ever go wrong with white.
Anyway next to a kitchen remodel the bathroom is a wise choice and if you can do it without changing pluming and walls it should not be too expensive.