Patterning tips?

[princess]

So I'm still enjoying piling hurt on myself, and I've decided that what I need to do to get motivated about the green monstrosity is add another layer of complexity. To that end I am looking for some good instructions to draft a doublet-esque style bodice (such as this portrait of Maria de Medici by Allori). I don't want to use a commercial pattern, but am rather trying to figure out how to do it on my own.

Thanks ahead of time.