First step is to get old cardboard and cut it into stripes and small pieces of your choice. The smaller you cut them, the more detail is possible to add to the overall shape. Start by glue a stripe around your head to fit its dimensions. Now build the basic construction with more stripes shaping a round sphere on your top head. (See first picture) second step is to fill the gaps with larger pieces of cardboard. (See second picture)
Step 1: Old Mattress Horns
Unfortunately we havnt made any pictures cutting the foam from old mattresses, but it's very simple with a sharp knife! You should use a marker to mark the basic shape and once cut out, you can define the shape with a sharp good scissor going smaller and more into detail. Simply glue them with hot glue and some pressure to the cardboard. Remember to keep it steady for a while to cool the hot glue down and give it the full strength!
Step 2: Add Plaster
To give the mask an individual shape, apply homemade plaster (take a look at my forest ghost tutorial). For the first layer you need to give it a good sweep to make it last. Then start shaping
Step 3: Add Colors of Your Choice
Take a brush and apply acrylic colors of your choice