Adding hand-drawn details to footage in Photoshop timeline

This doesn't look much different from the previous clips, but I've added some tablet-drawn paint effects frame-by-frame using Photoshop's animation timeline editor.  Took a while to figure out how to create a blank (transparent) video layer on which I could draw/erase one frame at a time, without having to create many new individual layers, and without disturbing the background footage layer.