Step 1. With compass on center, set its width to half the ellipse width
2. Move the compass to end of minor axis, draw two arcs on major axis
3. Label these, the focus points of the ellipse, F1 and F2
4, Tie a taut string between pins at the left and right side of the ellipse
5. Move the pins to F1, F2 and pull the string taut with a pencil.
6. Keeping the string taut, draw out a large arc all the way around.
Done. The ellipse has the desired width and height.