Obtain a hardwood tree limb between 32 and 98 inches in length and with a diameter between 2 and 3 inches. Choose a limb that is dead but not rotten. A live or green limb will be too wet to work with and will need to be air dried for about a year.
Securely clamp the limb in a vise. Strip off the bark using a draw knife and spoke shave.
Drill a 3-inch-deep hole in each end of the limb using a drill and a 1 1/4-inch to 1 1/2-inch forstner bit.
Shape the end opposite the mouthpiece with a spoke shave. This end is referred to as the bell, as you can flare it to resemble a trumpet's bell. You can also leave this end straight.
Shape the mouthpiece to a size large enough to comfortably vibrate your lips within the mouthpiece.
Carve the didgeridoo’s exterior to a cylindrical shape using a spoke shave.
Cut the limb in half lengthwise with a band saw.
Secure each half of the limb to a workbench with c-clamps.
Carve out the interior of each limb half using either a power carving tool or hand carving gouge. Remove enough material until the limb resembles half a pipe with uniform wall thickness of about 3/8 inch. This will allow enough surface for a good glue joint.
Apply wood glue to both halves of the limb. Clamp the limb together using c-clamps or hose clamps.
Allow the glue to dry for the recommended time. Remove the clamps.
Scrape the excess glue off with a chisel. Shape the didgeridoo to its final shape using a spoke shave. Sand the didgeridoo smooth with 120 grit sandpaper.
Test play the didgeridoo to determine if the mouthpiece is comfortable.
Adjust the size and feel of the mouthpiece by applying a ring made of beeswax to the mouthpiece. Soften the beeswax in a pot of warm water until you can form the beeswax by hand into a ring.
Place about 1/2 ounce of beeswax into a cat food can. Place the cat food can into a pot of boiling water until the wax has melted. Dip the didgeridoo's mouthpiece into the melted beeswax to form a base for the attachment of the beeswax ring. Press the beeswax ring onto the didgeridoo's mouth piece. Dip the didgeridoo's mouthpiece once again into the molten wax to unify the wax ring onto the didgeridoo.
Decorate the didgeridoo as desired with paints or wood-burned designs. Study Australian Aboriginal art for inspiration.
Apply a protective finish such as varnish or polyurethane to seal and protect the wood.