The trick for me was to put the end of the steam wand *just* below the surface of the liquid I’m steaming, wait for the screeching to stop, and then set the steam cup down and let it do it’s thing until it hits the top. It might spurt a little bit after you shut it off, so be mindful of that.
https://www.amazon.com/Breville-ESP8XL-Stainless-Espresso-Maker/dp/B0002VAFWA