You will need. Leather, scissors, xacto knife, paint, and water.
Step 1: Patterns
Find some patterns online or draw your own. Make sure they fit your face shape and you can see out of the eye holes and nose hole. Print out the paper and cut this out.
Step 2: Cutting Shape
Place fitted patterns on the leather you are using. Preferably one that you can stand up on its own. Trace patterns on leather. Cut them out with the scissors and the and the xacto knife.
Step 3: Shaping
For the perfect shape use your face, if not get the plastic masks from a hobby store and you can form to those masks just as easily. Wet the leather, just enough that it starts to conform to your face. Work the leather while drying. This will take some time so be patient. You may have to do this process a few times for the shape to stay.Let the mask dry. Try on once again and make sure nothing is poking your face, if it is cut if off and you are ready for painting!
Step 4: Painting
Let mask completely dry and make sure it is to your liking. Pick a paint that is leather specific, other paints will chip and fall off. Once done painting punch holes in both sides and use leather cord to tie the mask on your head. Enjoy!