Jonathan Williamson shares SO many things I'd never heard of before in Blender that watching this tutorial made my head spin. Awesome :)
Most of the mesh tools we use in Blender are used over and over again. Tools like Extrude, in most modeling workflows, are used hundreds, if not thousands of times a day. But there are a few tools that go relatively unused. These tools are easy to forget about, but when it comes to that one time you need it they’re really useful and can be quite a timesaver!
One such tool is Poke Faces. The poke faces operator takes all selected faces, places a single vertex in the center of the face, and then triangulates the face around that vertex. It can be very useful for creating all sorts of extrusions on the surface of your model. The example in the video, of a crystal vase, is just one of many use cases.