With remodels I always suggest starting with a "wish list" and an accurate "as-built" Floor Plan. Measure the space and use graph paper to draw the plan to scale 1/4" = 1'
Once you draw what "is" you can sketch what you "want" if this requires moving walls, it's best to bounce your ideas off a general contractor or design professional, they will help with "structural" advice and building code requirements. Enjoy your project!

Start with your basics such as what Kevin has suggested! Best of luck on your renovation!

Do u want modern or retro? Could be a cute retro pink, white, and black bathroom!

Kevin offered you some good advice. If you are going to knock walls down and raise the ceiling, start with a sketch of what you want the bathroom to be in Sq. Ft. and your "wish list" to have.

Talk with a contractor about relocating plumbing and electric, costs involved. A small master to large master remodel is hard to estimate. Demo, plumbing, electric and so on is pricey.

Come up with a list of what you have to have, do what work you're able to yourself (demo) and consider whether you'll be here long-term or if you see yourself in this house for a few years.

Hope this helps!

looks like ours!!

I'm liking the "retro"50's pink tile! It might work with new layout if fits with the overall design concept you are working with!

Moving the toilet is the most expensive part of the project. Can you keep it in its current location and build it into a toilet room? Then you can expand the bathroom around it. Good luck!

If you end up not demo'ing the wall tiles, they can be re-glazed to a white or off-white for a new-ish look.