As a ceramics student and a novice woodturner, I naturally succumbed to the desire to make my work as thin as possible. Thinner bowls and cups are lighter and more pleasant to hold. They are also much harder to create. Making thin work became the goal of my craft and the criterion by which I measured my level of skill.
It was not until I had achieved that goal that I realized what a false idol it was. The thinner the walls of a ceramic piece, the more likely it is to sag while drying or while firing to high temperature. The thinner the walls of a wooden bowl or cup, and the more likely it is to break or crack while drying. For both materials, the thinner the piece, the more delicate it is. There are even some times when thickness is a plus; a thicker ceramic mug will also hold the heat of your coffee longer. When focusing on creating functional things, the thickness is a definite design choice, and thin is not always better. (I could probably continue onto a life lesson on body-image but I will refrain.)
Here is an example of a porcelain cup for which I made a much too thin and delicate handle. Now this thin and delicate piece is relegated to holding teabags and instant coffee for use in a more practical mug.
Ultimately, the cup was more of a lesson than a successful piece. I was careless and broke the handle off so now it holds my stock of instant coffees at my desk at work. I still consider it a valuable lesson well learned.