After getting a fair amount of hair into my doll's head, I became quite concerned about how it wasn't laying flat. I'd experimented with styling doll's hair using hot water and even boiling water in the past so I decided that THAT'S what she needed.
I boiled the kettle, then poured the water gently onto her head while holding her hair down. I held her at an angle so I didn't get the water on my fingers. I could just as easily have poured the water in a cup and dunked her head in, but I like to live dangerously.
Well anyway, now her hair is laying flat, so I just have to wait for it to dry and then I'll continue. When I'm finished I'll do the same to the new hair and then go onto cutting and styling it.