Paint one wall with stripes! Frame coordinated pictures from a magazine or old book in monochromatic frames.
Master bath: Counter Intuitive - Take a cue from this bath's use of space at the end of the countertop. An awkward area between the wall and the edge of the vanity was filled with a narrow cabinet that's recessed into the wall. Open shelves store linens, and drawers below store other bath necessities
The only thing I would have to change in this space is the flooring. I would do a black & white check. That would give it that last bit of drama the space is lacking.