Place one end of wood at a right angle against the other. This is a box joint. Place a nail against the wood and hammer it into the other, connecting the joint.
Create a butt joint by placing the end of one piece of wood at any place along the second piece. Connect the two boards by hammer nails into the two boards.
Use a miter joint by cutting 45-degree angles on each piece of wood. Place each piece of wood into a miter box. Cut one piece at a left 45-degree angle and the other at a right 45-degree angle. Connect by hammering nails into the wood directly through the miter joint.