Follow the video instructions below if you want my version of the back carry.
There was no need, none at all, for me to go out and pay the kind of money I see these items sold for. I could have picked a better print, for sure, but I just needed something on the fly and that cost was too good to pass up.
I would suggest, if you've never back carried before, to do some practice runs with someone around. Use a chair if you have to or start out on your knees. I strongly suggest using a friend, partner, etc.
There is a different way to carry a baby that needs head support, an older baby, and a toddler. This demonstration was for a toddler, however you can make your own baby wraps/slings for next to nothing and with no sewing.
If you want a finished edge, rather than the raw one I have and you don't sew - get some binding tape from Joanns, Walmart, or any sewing notion store. You can get about 3 yards for under $3. If you get six yards, plus fabric for under $6, you'll have your own carrier for $12. Even if you spend more on fabric (remember to get light-weight fabric) it will still pale in cost-comparison from buying an actual baby wrap.
If you wish to buy an ACTUAL Kanga, visit Kangausa.com. They list themselves as, "Kanga USA is a project of Expanding Opportunities, a 501c3 organization and a registered NGO in Kenya. / Copyright © 2012 KangaUSA All Rights Reserved"