Pick an Altoid Case that will fit your iPod. I had a 3rd gen. nano which was perfect. Any flavor works. I used Wintergreen cause the colors matched my headphones.
Take your drill and make a small hole in the bottom right. (or wherever your headphones go in) Start with a small bit and work your way up or else your tin might crack.
Now add your Chair Pads (I don't know their real name...) This is just so that your iPod doesn't get all banged up while in the case.
Decorate your tin if you want. This is one I did for a friend's b-day. I used felt on the front and back with a ribbon handle and some nice stickers for some fun! Go crazy!
Now your done! Get out and show off your awesome new case and rock out to any tune you want. :D