Creating Shaped Vignettes in Photoshop

One of my students asked me how I go about creating vignettes that were specifically shaped to my subject matter. So I recorded a quick video showing the techniques I use to do so. I thought you might want to see it as well, so here it is!

[Make sure to watch it all the way through, as in the ending section I talk about the use of the curves tool as a much better and more natural mechanism for creating the vignette effect; the common use of an overlay layer can produce less natural looking vignettes]