1) Consider using an adult duvet print on a big boy bed. Accessories and toys can keep it younger. 2) Pick furniture that can grow with your kids. These shelves and crates are great for storing toys for toddlers and books for teenagers 3) You can find prints that work for kids and adults. Here, a beautiful nautical print makes kids and adults happy. 4) When considering a rug, try to stay away from baby-ish prints. However, feel free to go nuts with bright color. 5) Ugly Dolls are always the perfect modernist accessory for their modern kids. 6) Big Boy Built-Ins are a great place to keep toys and books neat and organized.  7) Think outside the single bed. 9) Similarly, keep the kiddo-stuff casual. Decals like that wonderful giraffe are the perfect way to add young touches that you don't require buckets of Killz a few years down the road! 10) When the playroom extends into the rest of the house, keep everything portable.