Plan to draw the cloud in the clockwise direction.
With the drawing displayed, click in open space and select Draw-Your-Own Detail, Half Ellipse.
Holding down the Alt key AND the Shift key, click a point on the desired cloud outline. Click again at another point on the outline. You should now have the first segment of the cloud as shown below.
Continuing to hold down Alt and Shift, click near the last point clicked and add the second segment of the cloud, see below.
Continue adding segments in a clockwise direction until you reach the starting point.
For more about DYO Details, see document K0027 on spoolfab.com.