To make an abstract sculpture out of polystyrene. Purchase a polystyrene block from the internet, you will probably find a supplier on ebay.
Draw our your shape onto the polystyrene with a marker such as a pencil or a permanent marker or felt pen.
Carve the main shape out with a hand saw or electrical hot blade.
Create more detail with a wire brush.
Carry on shaping the polystyrene with sand paper.
Remember to use a face mask.
When you have finished shaping the polystyrene it is then ready for painting or hard coating and painting or covering it with three layers of cement.