Here is an easy way to draw an ellipse by hand with a few basic materials.
Step 1: Materials
For this project you will need some string or yarn, two push pins, a writing utensil, and a some surface to draw on.
Step 2: Tie String
Now, take your piece of string and tie the two ends together so that it makes a big circle. The length of your string determines how big the ellipse will be. For a good estimate, half the length of the string will be a little bit more than the minor axis of your ellipse, depending on how elliptical your ellipse is.
Step 3: Draw
Next, push the pins in your drawing surface (a few inches apart) and put the string around them. Then, put the pencil at a third point on the string and pull outward as you draw around. An ellipsed should be formed.
The farther apart your pins are, the narrower the ellipse will be. The closer the pins are, the more the ellipse will resemble a circle.