Fig 1: Overlay Editor in action
Under Overlay - Draw Overlay you can draw and save new boundaries on the map. Selecting from the draw tool, you can add objects as points, line or polygons. When drawing a line or polygon, click for each vector and then double-click to finish. You can then modify the shape of the object by selecting modify, to click and move vertices or creating new vertices by clicking on an edge.
You can then edit the individual features, naming them, adding attribute data and changing colour and opacity. You can edit the features individually or as a group. You can then categorise and save the overlay for future use.