Pour cold milk into the jug up to the bottom of the spout. Remember to purge the steam wand before placing the wand into the jug about a ½ inch into the milk. Open the steam valve. Lower the jug after a few seconds to introduce air to the surface of the milk. Key here is texture first, then focus on temperature. Aim for a temperature of around 140-150°F, or 60-65°C. For non-dairy, try not to go over 130°F, or 55°C, as the milk can start to separate or curdle. Look for a velvety and silky-smooth texture.