Draw the profile shape with the 'Draw new curve point'
Use the 'Move Curve Point' tool to adjust points.
Right clicking will Close the curve, or use the Close
Curve icon.
You can move, add, delete, change sharpness of just one
or all points.
Click/dragging the central point of the control handle
will move the point.
Click/dragging the end point of the control handle will
change the shape of the curve.
To move the control handles independently, hold the Control
key while dragging.