We've always been advocates of a fun bathroom. Bathrooms are the spaces that get used SO MUCH but are low on the totem pole for design. Especially a secondary bathroom. A master bathroom will usually be the first bathroom to get some love AFTER the rest of the house has been furnished but the secondary bathrooms? Forget it. You might as well call them the red-headed step children of the house...maybe before the basement, though.
The nice thing is that secondary bathrooms are small spaces so it's good to remember that, when you're designing them, they won't take up a lot of material. The art is usually going to be smaller, the rugs less expensive, the paint quantity less...you see where I'm going? Yes, hard surfaces like tile and granite ARE a little more, but if you're just trying to freshen up a bathroom without doing much with the hard surfaces, you don't have to spend a ton of money.
A typical bathroom that just needs to be freshened up probably doesn't have a ton of pattern. So consider bringing in a fun pop of pattern in art or a cool shower curtain. Of course, there's always our go-to pattern popping tool--wallpaper! Just something new and different to liven it up! No matter how small your bathroom is, there has to be one little piece of wall space or floor space that could hold pattern.
Maybe you're happy with your art or your bathroom just doesn't need too much pattern. Start thinking about the functional pieces in your bathroom that could be swapped out for something more interesting. The vanity mirror can be a big statement piece...or it can just die. In a large master bathroom, we like the idea of frameless mirrors that go all the way to the ceiling and have lights inset into them. However, in a secondary bathroom or powder bath, where there isn't space for much else in the way of decor and focal pieces, a mirror can easily be a fun piece of art. Consider swapping yours out for something that's a little more fun. Or, if the bathroom isn't used much for "getting ready", you could even used a grouping of mirrors that allow someone to check their face but is a little more fun to look at than one solid mirror.
Most bathrooms have enough space for an additional piece of storage or some shelving. Selecting something that's more of a contrast in the space is another easy way to add decor and function. An etagere or small glass cabinet that can hold additional guest towels, room sprays, toilet paper...maybe even a cute book. Just be sure to style your shelving well in a bathroom. Open shelves with a bunch of clutter are the last thing someone wants to see!
Finally, consider updating your cabinet hardware and accessories. If you can swap out your faucets, great, but we're not in the camp that believes everything should be so matchy-matchy. Fun cabinet door hardware with some updated towel bars, toilet paper holders, and towel rings can really jazz up a little bathroom. So many people take those finishing details for granted but they matter!