I wanted a bathroom with gender neutral colors for my son and daughter as they will share this growing up. I also didn't want a bathroom that I would have to update in the next 5 years, so I stayed away from using characters or decals on the walls.
I used the following:
Threshold Paisley Shower Curtain (Target)
Threshold Paisley Bath Mat (Target)
Room Essentials Grey Bath Mat (Target)
Sonoma Good For Life- yellow towels (Kohl)
Behr-Grey Marble (Home Depot)
I waited until the Target items were discounted through Cart Wheel.