To add a vertex to the freeform, click where you want to add it, and then drag.
To delete a vertex, press CTRL and click the vertex you want to delete.
Tip
For greater control over the shape of a curve, after you click Edit Points, right-click a vertex. Use the shortcut menu (shortcut menu: A menu that shows a list of commands relevant to a particular item. To display a shortcut menu, right-click an item or press SHIFT+F10.) to add other types of vertexes to refine the shape of the curve.