JRob needs get his video done, before we have to hurt him Seriously, though, these diagrams on measuring a wig tend to contradict one another. They leave out some critical information, like exact starting points etc....

I found this on Youtube, <!-- m --><a class="postlink" href="http://www.youtube.com/watch?v=QmhLozrcMGI">http://www.youtube.com/watch?v=QmhLozrcMGI</a><!-- m -->, but most sites out there have slightly different instructions.