What are the criteria for creating methods in the class?

Is it better to write a method and function from the top and have an api function that has a lower stack as you go down?

Conversely, is it better to write an important api function first and put it at the bottom as the stack is higher and more peripheral?

Or should we write a peripheral, or associated, method that's just used for that API function right in between?

Or is there anything else better?