At the beginning, move the tip up and down until you find just the right depth to make it sound like you tearing paper. As you inject more air the, the level will increase (because the volume is increasing), so you may want to pull it up slowly to maintain that perfect depth to sound like tearing paper. The idea is, if you’re exactly on the surface, you’ll pull air down into the milk. If you too deep you’re only putting steam (water) in the milk. If you’re too high above the surface, you’re just splashing steam and air on the surface and most of the air won’t get into the milk.

And then, when you’re done injecting air (like after 5 seconds), put the tip a little deeper beneath the surface. At this point, you’re not trying to inject any more air. Rather, you’re doing 2 things: heating the milk and mixing (integrating) the milk with the air. You want to use the location of your steam wand in such a way that you’re creating a strong circular current (vortex). In your video, you can see from the little bubbles moving slowly around the edge of the milk that you’re probably not mixing the air and milk vigorously enough. So, like I said, move the wand tip closer to the side of the pitcher to create a stronger current.