Maybe nail shelves to the back of bookcases for more book storage?
DIY Cardboard Box Washing Machine – Little Girl Toy and Room Decorating Ideas
Ikea Kallax Custom Cushion for Nursery, Playroom , Organization Bench Cushion Seat Expedit Replacement
Playroom Idea - DIY Projects Featuring the IKEA Lack Table I like this idea. I'd probably find an inexpensive coffee table, paint it, and then glue Lego base boards to it.
diy reading chair made from two wooden palettes. I just like the idea of a huge reading chair. Making use of all the corner space makes sense!