Draw a vertical line on the left side of your staff sheet. Compare it to a sheet of music that already has notes on it to make sure the location is appropriate.
Starting from the second line on the staff sheet, draw a capital letter "G." To make it properly, Piano-Play-It.com, an online piano playing website, recommends setting the boundaries of the belly of the G to the third and the the bottom line. To some, this will look like a letter G, while to others it will look like either a spiral or a number 6.
Move to the other side of your horizontal line and draw a semi-circle to the edge of the vertical line. This semi-circle should begin at the top portion of the G (or 6) that you drew in Step 2.
Add a curved tail to the bottom of your vertical line. The thickness of this tail can vary by whatever look you may be going for, but it should ultimately appear as a slightly-askew comma when drawn properly.