Implementing a Custom Flavor

Does anyone know how to implement a custom flavor?

I assume it is defined in the User Interface --> Mapping --> Flavors area of System Administration.

Once a new flavor is created, how can you use that new flavor in a custom layout?

My assumption is you have to assign the new flavor to a given renderer (say collection renderer), then reference the flavor in your layout controller.

Is this correct? How do you reference it in your Layout Controller?

Thanks.