Some tips for drawing an evil clown are to start by drawing the main forms of the clown and to draw the eyes smaller and farther apart than on a normal face. Another tip is to re-shape the original jaw line into a more sharp and pointed chin.
When starting with the main forms of the drawing, outline the shape of the head, and add guidelines for facial features such as the eyes, nose and mouth. Since the drawing is not of a normal face, it is okay to position the facial features in different ways such as drawing the eyes higher than normal or making the mouth larger than usual. Drawing the eyes smaller and farther apart helps give the clown face a more sinister look. Shaping the chin so that it is more sharp and pointed gives the clown a more imposing aspect.
A good idea for the mouth is to draw it open with an evil grin that shows pointy and twisted teeth. Add wrinkles between the eyes, on the forehead and around the mouth to define the evil facial expression and add depth to the drawing. For the lasts steps, add the red nose and some creepy clown makeup around the eyes.