When tracing an image in Illustrator, it is important to use the Pen Tool to create a clean line. This will help you avoid any mistakes when tracing the image. To start, hold down the Pen Tool and drag a line down the center of the image. Make sure that your line is long enough to cover the entire image. Next, use the Pen Tool to make small circles around each of the lines that you just drew. These circles should be close together so that they form a smooth surface. Finally, use the Pen Tool to make small lines between the circles and lines that you drew earlier. These lines should be shorter than your circles and should be perpendicular to each other.