It's a bit late, but may help someone else, so I'll pop it here. Basically it details how to get the shape of you head:
Wig blocking/head wrap
This is a technique that allows you to create a ‘template’ of your head shape, that can then be added to a cheap polystyrene head. You can then use it to style you wig on. It also helps to see where your own hairline is if you are styling a lace front wig.
You need 2 people. Clear tape, A marker and some clingfilm.
Put your hair up like you would if you were putting a wig on, ie hair net, pin curls etc.
Wrap the clingfilm round your head so its like a hat, the tape it down using quite a bit of tape. Then draw round your hairline and mark where your ears are, cover that in more tape so it doesn’t rub off and wiggle it off your head.
You will notice that your clingfilm template is bigger then the wig stand, you want to pin your clingfilm at the front tape it down and start to pad it out, tape round the edges. make a slight cut in the top to stuff it, just make sure you tape it back up. I usually wrap the whole head in clingfilm after that and tape it, then you can use it to hot curl a wig. To make it more stable to work on you can attach the wig to a small square of MDF. You now have a template of your head to work on.
https://www.youtube.com/watch?v=Tsm3FZ7AhrY
https://www.youtube.com/watch?v=3WjsBAsBXKg
https://www.youtube.com/watch?v=Ewrh1QgpU6A
