Issues Decorating Moulds with White Chocolate

Hi Everyone,

I have just started creating moulded shoes and was using white chocolate to decorate them (with dots). So I put the dots on the mould and let it set. Then I add milk chocolate to create the shoe. Sometimes when I un-mould, the dots stay stuck to the mould and I'm left with little craters in my shoe. Any advice?

I've attached a photo of a shoe that looks ok and another with the problem.