For my final project, I decided to make a crusader helmet. I began by extruding a cylinder and cutting the shape of the helmet into it.
I then sketched the cross shape and holes on the front of the helm. I decided on a conical helm, so I sketched an arc on the top of the helm and revolved it around. To hollow the shape, I made a smaller cylinder and cut it through the shape. The final product looked like this:
The final product took 31 grams of PLA and 5 hours 10 minutes to print on an Ultimaker 3.