I made this set out of boredom *weee!*
There are many ways to go about editing hair, this is just one technique. I find that little details like hair tendrils/strands can really make a doll stand out. Notice the difference between the cropped version and the finished one.
Also cloning and combining may not always work as you can get left over splotches of background that would be hard to hide or blend into your set.
-If your going to put whole sections of hair, clip along the hairline (i.e tendril, hair piece of the original pic) and then place behind. Make sure the hair color matches.
Anyway hope this helps someone. Happy doll Making :)