Contour Editor

Use the Contour Editor tool to change the shape of a pencil line or a brush stroke.

To add a point, press [Option] and click the line.
To move a handle on a point independently from the other handle, press [Command] and drag the handle.
To remove the angles on the handles, press [Command] and click the point.

To activate this tool:

Select Tools > Drawing Tools > Contour Editor.
Select the Contour Editor tool from the Select menu on the Drawing Tools toolbar. If the Contour Editor tool is visible in the Drawing Tools toolbar, press [1] to activate it.