Mommo Design has a bunch of inspiration for girly reading nooks. These quiet corners contain fluffy pillows, rugs, cushions, usually a canopy, and of course lots of books. I think the idea is very cute and I'd love to do this for my daughter's room.
Don't have much space to grow your favorite plants? Try building a vertical garden like this one, designed by Susie Frazier. Using salvaged wood, threaded rods and bolts, and a handful of mason jars, you can construct a simple hanging planter to add a lot