Hi! Sorry I didn't get to this sooner.
About the vests:
My DH designed the skull and crossbones on the computer. We printed them out and used the printouts as templates. We cut the designs out of a stiff white felt and glued them (with nostitch sewing glue) to the vests (which my mil made out of a black fake suede material).
We tried several different characters. I know we did Winnie the Pooh and that just looked so wrong. We tried to keep all of the characters white but Minnie didn't look right. DD8 walked by, looked at the design and said, "She needs her red bow." And it worked.
DH sized the characters too. We had a group from 21 months old to 65 years old. Our sizes ranged from 2T to Pooh sized adults and everything in between so what looked good on one person looked too big or small on another. The adults' were all fairly close in size though.
I'll see if I can find the individual pics we took.