Mei was actually the favourite Overwatch Yarnling I made - at least I felt she resembled the original character the most. I even made her fatter than the other girls in the series (!!!). 

Through some trial and error (and some great internet resources!), there are 2 ways I used to make hoods for my Yarnlings:

Ways I incorporate wires into my Yarnlings.

Through a lot of experimenting, I have come up with a series of different ways to make amigurumi hair: