I tend to meet at a location (such as a centrally located Starbucks) to drop off the cake. It avoids having to give directions to my house, and also promotes being on time. I have never had anyone late to a meeting at a location such as this. I guess they view it as different then my house where I'll be home anytime and they can just drop by.
It is easier for me too because I can plan around that meeting instead of waiting around for them to show up. It works for me!