Before you apply varnish to wood be sure to clean the surface of the wood. Use a foam brush to apply a thin coat of varnish to the wood. Once the first coat is completely dry, sand the piece, clean away the dust, and apply a second thin coat of varnish.
From easiest to hardest: With a saber saw. With a band saw. With a coping saw. With steaming and then bending a thin piece of wood. With cutting close kerfs in wood, and them bending it mechanically. With careful hand carving.