Take notes of special features in the room. This can include the location of a closet, or some kind of aberration in the design of the room.
Draw an outline of the room, without worrying about scale, but noting the location of special features mentioned above.
Measure the room so you can make your sketch to scale. Make notes of these measurements on your rough sketch.
Draw your final sketch on graph paper. Use a protractor to make sure any angles are at the proper degree, and a ruler to keep your lines straight.
Create a legend showing how many squares in the grid equal a foot or inch in your sketch.