The best kinds of DIY projects are those that can be done quickly & on the cheap. This project is functional, good looking, and won't break the bank! Minimal supplies are needed too. What could be better?
All you need is IKEA's multi-sized PRÄNT boxes, a selection of your favorite paint colors, and some of those little office clips. You can mix and match different sizes of the PRÄNT boxes for a unique look. I suppose you could do a simple grid too if symmetry is your thing.
See the full DIY at IKEA's Blog. Make sure to translate!
Images: IKEA blog