Select a block of Styrofoam to carve. If you cannot find one that is large enough, glue several blocks together with industrial rubber cement, painting a layer on both sides and pressing them together once the glue has dried.
Sketch the outline of the sculpture on all six sides of the foam block. Each drawing will represent the statue from a different perspective: front, back, left, right, top and bottom. Avoid overly delicate forms such as a cat's tail or a pointing finger, as these will break off easily.
Carve out the rough form for the statue using an electric carving knife. Work in a large space and wear goggles, a particle mask and long-sleeved clothing as you work. Styrofoam chunks and dust will get everywhere, and because cutting charges the Styrofoam with static electricity, the chunks and dust will also stick to everything.
Refine the details of the statue with a hand-held heated wire tool. This is basically a loop of wire that gets hot enough to melt the Styrofoam. Open windows for ventilation as Styrofoam releases fumes as it melts. Hot wire cutters are available in a variety of shapes and sizes.
Sand the Styrofoam with a coarse sandpaper,16-150 grit, then smooth the sanding marks by rubbing them with chunks of foam that you had cut off previously.
Add fine details such as wrinkles and fur with a soldering iron. If your sculpture does not have any delicate details, skip this step.
Paint the finished sculpture with latex paint, either with a brush or latex-based spray paint. You can also use water-based craft paint.