I used one of those metal Altoids mints holder for this lipstick case. If you're a sticker collector like me, all you have to do is gather some of your favorite stickers together or you could even break out acrylic paints if you really want to get fancy ;)
I carry my lipstick, those small perfume samples, a spare battery for my voice recorder, and any loose change in my case. I have another box that I'm going to use as a business card holder.
What kind of projects are you doing for Earth Day?