Seam problems

I am having problems with sewing the fur for my fursuit head at the moment. The fur crinkles and folds into itself making weird angles to work around. I'm not sure whether the way I'm sewing the pieces together is correct or if I just didn't completely sew all the pieces of the head together again
Here is a picture of the top of the forehead area of my fursuit head:




and here is a picture of the seams underneath the forehead region:

This is my first fursuit head and first time using duct tape as a pattern so I've been running into many problems. Can anyone tell me what is the best sewing technique to use for this type of sewing?