From a mention elsewhere on the boards, I stumbled across an out of print (and copyright) book available for free online called "The Studio And What To Do In It" by Henry Peach Robinson written in 1891. I read it start to finish in an hour and, by the end of it, I was wanting to bash out the ceiling and hang some curtains.

Unfortunately, I think my landlord might object!
Anyway, it makes some good suggestions for controlling light, as well as pointing out ways to flatter your subject and diminish their, um, less than favourable aspects, shall we say

The book can be found here, if it's of any interest: