Get any type of cardboard material you want, tape and a type of sharp tool.
Step 1: Cut Front and Back of Your Phone
Cut the cardboard to fit the size of your phone you will want two pieces the front and back.
Step 2: Cut the Sides of Your Phone
Now after you cut the front and back we now have to do the sides.
Step 3: Finish
Put the pieces together by taping or glueing.