Hey there, yes, create the template as you go and refine it as needs be is a good way as it is based on experience.
Still, grab what you can of outlines, why's and whatfor's when compiling docs as well as why you are doing it to get a respectable one all proto'd out.
Another plus is that you get a lot of fun out of going back and forth plus a record of what you did when you did it (complemetry documents of course... ad infinitum)