How and when to get paid. What you need to do with the contract once it's signed.
Holding up your end of the bargain whether your licensing previously-made pieces or custom-made pieces. What will happen after the art is delivered.
A post mortem doesn't have to be very formal, but you want to take note of what went well, what didn't, and ideas you have for future licensing deals. Here are some questions I like to answer in a post mortem.