Question: how to decorate a key?
Answer: Wrap the top of the key in yarn, like Crème de la Craft. ... 
You can use nail polish to color code keys, as seen on A Bubbly Life. ... 
Or use glitter polish to give it some sparkle, a la Ramshackle Glam. ... 
Washi tape (like on Cinema & Spice) makes it easy. ... 
Scrapbooking paper (like Crème de la Craft) makes it even easier.