It would be difficult to plan accordingly without knowing more details: is this an existing or newly built space? Are the external walls on the front or other sides of the house? Regardless, here's some food for thought, sans the bathtub (it could also be a tub/shower combo).

I am actually adapting a plan I found, and just couldn't make the master suite work. The external walls are on the front and side of the house. Thanks for the sketch, I like how it uses the space.

Here is a very crude drawing, but it might give you some ideas. I would probably use café doors on the toilet entrance.