The Stormtroopers were primed in P3 White primer, and a detail layer of Mechanicus Standard Gray added to the dark parts of the under-armor and gun.

The left figure has had 3 coats of highlight applied, the middle only one, and the right is without highlighting.

Finally, the first Stormtroopers were finished.  Testor's dullcote was applied, then a layer of GW's Ardcoat on top to make them shiny.

Here are the first, poorly painted Stormtroopers facing off against their unpainted counterparts.  Even with the interesting lighting on the gray ones, they are better at drawing the viewer into the setting.

His tutorial videos are so good, even my son wants to paint.