I have some gum paste circus decorations that I would like to do in advance for a baby shower cake, what would be the best way to store them or is it best to cut them out the day I cover the cake in fondant.
Gumpaste pieces can be made days, or even weeks, ahead. Store them in a non-airtight cupboard, drawer, or container on paper towel. They will dry hard and keep for a long time. I'm suggesting a cupboard or drawer, because if the pieces are coloured (in particular, dark colours), they may fade over time if kept in the light.
If you use a mixture of gumpaste and fondant, they will take a bit longer to dry. Gumpaste alone dries fairly quickly.