Make sure you have the preview box ticked to be able to see what’s happening to your drawing when trying the different options. Set the tracing options to Mode: Black and white; Threshold: 118; and Blur: 0. You don’t need to use the options on the left of the box. Your image is now traced. Select and highlight it. On the top bar, you will need to click the Expand button to convert the tracing object into path. Your image should be now highlighted with blue dots, and the sketch is vectorized.
Holding down the Ctrl key, click on your mouse (right-click on Windows). On the window that appears, select Ungroup. It is better to separate out each element of the scanned sketch so they are independent from each other. When the image was saved as a JPG, it acquired a white background. Click on the white space next to the elements of the image in order to highlight the background. Then delete it. You don’t need it.
As you have probably observed, the image is now a vector but it looks far from clean and sexy. Each individual element of the image will need to be adjusted to achieve the finished look. We’ll start with the eyes, as they are the first thing that people will look at. Select and highlight one eye from one of the women.
Select the Smooth tool from the toolbar palette, and apply it around the eye until you have a shape that looks correct. It is best to use this tool as if you were drawing naturally with it. Apply this technique to all the eyes of the illustration. Don’t forget to zoom in your image for greater precision.
Now, that you have correct shapes for the eyes, you need to work on the second element that will make each of the women look even sexier: their mouth. Some of the mouth shapes will just need to have the previous technique applied. For others, you will have to draw them from scratch with your mouse, using the pen tool.