elliptical selection

  1. Choose the elliptical selection tool

  2. Place it where you want the OUTSIDE EDGE of the ellipse to appear

  3. Click the left mouse button

  4. Dag the cursor to the desired OPPOSITE SIDE of the ellipse

  5. Let go of the MOUSE. Presto.

This seems simple and intuitive, but I spell it this out clearly to differentiate from starting a rectangle or ellipse from the CENTER, as opposed to the default of dragging from the outside (as is shown here.)