Rosetta is probably the easiest and hardest latte art pattern to pour as it's easy to get started with but hard to master. Here is my guide how to pour a latte art rosetta pattern and what to consider when pouring the rosetta.
Start by pouring from a bit higher to the middle of the cup. This way the milk will sink underneath the espresso and you will get better contrast to your latte art - sharp pattern and bright brown outsides. This start is called "brown cup" as you are trying to keep the cup brown.
The brown cup phase you might want to pour everywhere in the cup to keep the drink moving. This will break surface tension which lets the patterns to spread in the later sections. Keep in going with this until the cup is about 50% full.
WIGGLE AND POURING THE PATTERN
Once your cup is 50% full, you need to move closer to the surface of the drink with your pitcher. See the picture above how close the pitcher's spout is to the drink's surface. Now we will start pouring the actual pattern. Pour again to the middle of cup even though the pattern will move to the bottom of the cup. By pouring "fast" you will get the pattern to spread and move to the bottom.
Once you notice that the milk is starting to accumulate to the surface, start wiggling your pitcher and keep on pouring "fast" to the middle. The wiggle will create the wave pattern that will eventually create the rosetta. Continue the wiggle all the way to the end.
Once you notice that you have created large enough base for the rosetta start backing up with your pitcher and keep in wiggling.
Back up and wiggle until you are almost in the edge of cup. Stop the wiggle and pour for a second to one spot. This will create a heart to the top of the rosetta and at same time "stiffen" the pattern to keep its place.
It's time to finish and divide the pattern. Lift your pitcher just 1-2 cm from the surface of the drink and start pouring through the rosetta. If you pour too high, the pattern will sink underneath the surface and if you pour too slow the rosetta won't divide well.
Serve the good looking rosetta with smile! :)