Using the circular saw, cut fiberboard to the dimensions you want for your headboard. If you wish to add fabric-covered buttons for a tufted look, drill 1/4-inch holes into the fiberboard at desired locations (optional).
Using the fabric scissors, cut the 2 layers of batting to a size 3 inches larger than the dimensions of your headboard, all around. Cut the fabric you chose as your cover to the same size as the batting.
Wrap the layers of batting around the fiberboard, pulling tightly. Staple them to the back of the fiberboard using the staple gun.
Lay the headboard batting-side down on the wrong side of the cover fabric. Pull the fabric tightly around the board, stapling securely as you go.
If you'll be adding buttons to the headboard, push a needle and thread from the back of the board through the holes you drilled earlier. Pull the thread through the button loop and back into the hole. Repeat until the button is secure against the headboard. Pull ends of thread tight and twist around a brad nail hammered to the board back. Do this for each button.
Attach the headboard to your bed frame or the wall behind your bed.