Use Bezier Mode to draw shapes with finely graduated curves. Control the exact shape of the line using the black handles to either side of the points you place.
Click to place Corner points, or click and drag to place curve points with handles.
For information on Control Points and the other Bezier Line editing tools, see Convert Points and Bezier Lines.
The Point Create functions may be easier to use for the exact positioning of corners, straight lines and curves than the Freehand Create functions.