Sketches are an essential part of the design process, and really help when I'm trying to explore form and functionality. Here are a few of my highlights;
Pet diffusers
Toothpaste packaging
Some of my projects require my sketching to go into detail, to really show the reader what I'm trying to show or prove.
These sketches, for example, were essential to show how my tube of toothpaste can be squeezed the same as any other, which is essential to be a successful product.
Examples
Lamp/dumbbell