ProcJam is coming, and that probably means that there are a bunch of you who are trying to figure out how to create meshes in Unity from scratch.
Well, this video should help with that. While it is specifically focused on extruding a shape along a spline to create a new mesh, many of the technical details are important considerations for creating any mesh in Unity.
This stuff is also useful for people who aren’t using Unity, though some of the technical details will be different if you use, say, a right-handed environment.