Depending on where you are, your interpretation of Asian style design will be different; here in North America, we generally rely on Japanese inspirations for Asian designs. This means emphasis on ceremony, relaxation and bringing nature inside.
Bathing and other bathroom activities are considered separate in many Asian cultures. Separate the bathtub from the sink and other areas of the bathroom as much as possible. This isn’t always practical with the way Western homes are built, but this example shows a good solution to creating that reflection space for the bathtub.
Considering with how important bathing is in Asian cultures, soaking tubs are very common. Copper and wood soaking tubs are most common.
Sound is very important in Japanese design. Water should pour or trickle out, not spray out. The more like a spa your bathroom sounds, the closer you are getting to an Asian design.
Lots of natural light is important. If you aren’t lucky enough to have a large window like this, skylights, light tubes and reflective surfaces can all help increase the natural light you have.
Asian craftsmen built everything by hand, using regional wood, leather and stone. Cabinets and shelving should retain the wood’s natural grain and color.
Color schemes can be anything natural. Plant-like greens, sunset orange or even ocean blue, but most of the time, the beautiful natural wood and stone will provide enough interest and the only color you will need to add would be plants or some simple artwork.