For the green bathroom painting the vanity white and replacing the cabinet hardware could really elevate the space. Another easy addition would be putting a fun art piece above the toilet!

For the half bath, take down those shelves, change out the light fixture and get a large print wallpaper on all walls. Try to hide the trash can.

I would go with higher rod and longer curtains.

Check this video how to do some update for bathroom. I like it. The same cabinets color and countertop as yours.

Paint, wallpaper, and better lighting. And a designer's eye.

i agree some VERY STRIKING wallpaper would uplevel this - along with removing the two shelves that seem to hold nothing that is necessary and make it a bit busy. IF affordable get a new round or long LED backlit mirror and forgo the fixture overhead. I love Houzz but think the options for wallpaper on Etsy are far more dramatic - find what YOU LIKE, but really love the wow factor of ones like Chispa posted below. here is another that is completely different but both are bold and would work with your already black fixtures. Would get a real pop of interest without alot of expense. https://www.etsy.com/listing/1378853348/chinoiserie-wallpaper-peel-and-stick?click_key=94e9402f482a16060d43df2997c938fa0d6b975d%3A1378853348&click_sum=dfe43d44&ref=as_recently_viewed-1&pro=1&frs=1&sts=1