I recently discovered a craft blog called Minieco, created by Kate Lilley. She's the author of a book called Eco-Friendly Crafting With Kids. Her blog is filled with tutorials for making colorful and artistically refined things out of simple materials (often colored paper.)
Kate's sense of style resonates with me -- I see touches of Charles and Ray Eames and Mary Blair in her work. She also is inspired by retro-design, as you can see in her 8-bit popup cards. Check out her full tutorial.