I began with a plain Nokia 6020, 3 years old. I changed the original case as the paint was all but chipped off. I kept the keypad however, because the keypad of the original remains the best (most sensitive).
I bought a fake Nokia 6020 case with matching keypad and kept only the case for my purposes. I didn't want to buy an original because this phone is more than 3 years old, and the original cases have long been pulled out from stores. Besides, if I failed at this, I would feel terrible spending thousands of bucks on an original case.
I bought some rhinestones from Saizen (the legitimate local affiliate of Daiso Japan) and in all my trips abroad before decoden became really popular here, so all I needed were my tweezers and clear nail polish, and then I was set!
For those in Poupee, you may Suteki and comment at http://pupe.ameba.jp/item/34hSx34lh