Balsa is the lightest and softest hardwood. It has a wide range of uses, from insulation to packing material. It was even used in life rafts and battleship armor plates in World War I. Balsa wood grows naturally in the West Indies, Central America and tropical South America. It is most often used nowadays for making models, such as airplanes or boats, but is also used in life-belts, water sports equipment, theater props and dishes.
Sketch out what it is you want to carve from the balsa wood. Many model-builders use balsa for model boats and airplanes, but you could sketch out model people, bowls, decor and so forth. Sketching out your idea will help you figure out the dimensions and measurements. Buy balsa wood in sheets or blocks from craft, hobby or hardware stores. For detailed object carving, blocks are best, and for model building sheets work better.
Carve balsa wood by holding it in one hand and turning it against the knife's blade while carving away thin strips or pieces. Use your thumb as a guide to make the curves as smooth as possible.
Hollow out objects such as boats or bowls by cutting away the top section evenly. Use your fingers to grip the balsa wood while you make a deep slice down the side. Continue to slice downwards as smoothly as possible. It is best to cut small, thin strips rather than large strips, so you don't mess up and have to start all over again. Continue to shape the balsa wood into the object of your choice.
Sand down the outside of the balsa wood carefully with a light fine-grit sandpaper. This smooths the wood and helps polish the shape.
Paint or stain your carving, if desired. For model boats and airplanes, paint on the details.