Place a new graph paper sheet onto a clipboard, securing it with the clip. Make sure that the paper is not creased or wrinkled.
Stand in one corner of the room. Begin sketching the wall onto the graph paper, following the grid lines as closely as possible. Use a ruler if the lines are difficult to follow.
Follow the wall from the corner until the entire room is sketched onto the graph paper.
Sketch a vertical line at each wall corner. Make sure that each vertical line is placed on the outside edges of the graph paper, allowing the middle space to remain open. In addition, verify that the vertical lines are drawn at each wall's inside corner mark.
Draw a continuous horizontal line through the vertical lines' top portions for each side of the room on the sketch.
Measure each wall section with a measuring tape. Record the numerical value, in inches, on top of the horizontal line. Make sure that the measured section is notated on the correct portion on the sketch.