Learning how to draw an ellipse by hand is essential because it's the foundation for drawing most any subject.
First, it's important to not confuse ellipses with balls.
TIP: Always, always draw the entire ellipse. This allows you to get it proportionally correct, which is virtually impossible by just sketching the front rounded section.
An ellipse is a contracted circle . . .
When you draw an ellipse it is all about understanding where it is located in your plane of vision (rather, what perspective you have), and this will tell you how narrow (contracted) or wide (expanded) it is to be drawn.
TIP: When you draw an ellipse it narrows or widens (contracts or expands) in the vertical direction (up and down). However it stays the same in the horizontal (across) direction.
Let's begin with a cup, looking at the rim with your plane of vision being at eye level . . .
Ellipses become more contracted (height is diminished) the nearer they are to your eye level.
The nearer they are to your plane of vision, the more "flattened" they becomes.
When you are viewing the top of a cup straight on (at exact eye level) with no angle, the ellipse will be a straight line -- a completely flattened circle.
Notice that the rim and bottom of the cup are not to be drawn the same size (a mistake often made)
When you are viewing a cup (or anything cylindrical) from an angle, the rim and base are not an exact same sized ellipse. This is because the rim and the base are at different eye levels (they are in different planes of vision).
For instance when the rim of the cup is at eye level notice that the bottom of the cup is not, it is slightly below. Therefore the bottom will be drawn as an ellipse when the rim is only to be drawn as a straight line.
The ellipse begins to widen as you view it from a higher perspective (or angle) . . .
Notice again how the bottom ellipse is wider than the top one.
The cup is also drawn shorter to represent foreshortening, as your angle of view is higher.
The higher your viewpoint, the wider the ellipse will appear . . .
Also notice that the foreshortening of the cup becomes a lot more evident here. Draw the section (illustated by an arrow) shorter as the cup foreshortens.
TIP: The cup will look fatter even though it is not. It's just that you are seeing more of the ellipses (they are expanding) than you are seeing the side of the cup.
If you look straight into the glass, it will be a full circle . . .
This is as foreshortened as it gets!
Completed Cup . . .
This is the second cup version from above. I erased the draw lines and finished it with shading.
You can easily learn how to draw a cup once you learn how to draw an ellipse!
Creating art and crafts builds new neural pathways in your brain and is a great way to keep your noggin healthy. Keep creating for optimal brain health!