over powder/ over shot wad maker?

[Mr. 16 gauge]

Being a do-it-yourself kind of guy, I'm looking at my box of coco puffs this morning at breakfast and thinking "I could probably use this box to make over shot wads". I'm also thinking I could use the backs of old legal pads to make over powder wads. All I need is some kind of punch.....check a few web sites and few carry punches of this size; those that do want a small fortune for them!
Does anyone have a way to make them using some common house hold item as a punch? If I come up with something, I'll let you know......
Thanks in advance..........