My FI and I decided from the beginning our cake was not importent. We were going to skip it all together, and spend the money on our honeymoon, but a friend of ours wants to get into cake decorating, and offered to make our cake. She was really excited about the idea, and we were happy to let her use our cake as practice. She needs to buy supplies, and I know it can pricey, so how do I offer to cover the costs? Do I just come out and ask for the receipts?