The guest bathroom recently underwent a complete overhaul, complete with floor demolition and plumbing updates. The old drain pipes were still made out of lead and the old cabinet was some seriously deteriorating MDF-vinyl affair!
From our other small bathroom, I had already learned the completely counter-intuitive trick that tiny, well-lit spaces do really well with dark wall colors. The dark walls recede and actually make the space feel bigger - a very strange optical illusion that I think is heightened in this case by the sharp contrast with all the white tile and fixtures. We went from this:
Here is a shot of the other side, with the fun tree curtain I found for the bathtub. Before: