When we make latte art, there are three points coffee valve wants to tell you need to pay attention to: flowing velocity, distance and pouring position.
Flowing velocity: the speed that milk start being poured from the pitcher. The higher the speed is, the more the foam left; the slower the speed is, the less the foam is, and there's no foam on the surface, you are just pouring some milk to the coffee instead of making latte art. So controlling the flowing velocity modestly can conserve enough milk and leave sufficient foam on the surface.
Distance: the height of pouring the milk. the higher the height is, the milder the milk blends into the expresso; the lower the height is, the easier the foam appears on the surface of coffee.
Pouring position: the position the milk is poured in the coffee cup. We should pour small quantity of milk into the middle of the coffee cup at the beginning. When the cup is half-full, pouring the milk directly to the cup, the closer the better. When getting close to the coffee cup, maintain the pouring speed.
At this moment, the pitcher still direct to the middle of the coffee cup. After all the milk is poured, shaking the cup slightly. Shaking it slightly rather than swaying it or moving your arm. Remember hold the pitcher tightly and control it well, don't make the pitcher sway.
We can see a layer of foam like a leaf flows. Drag the pitcher backwards when the leaves piles up; lift up the pitcher and lower the pouring speed, drag it forwards in a line. Now, a cup of coffee with a latte art leaf is done!