Soften butter properly. See attached video tutorial for detailed instructions for the best way to make refrigerated butter, room temperature in seconds.
Gently flatten dough. This step in the recipe is crucial for achieving delicate, consistent, and even cookies. Lightly drip the bottom of a glass cup in flour, shake excess flour off of the bottom. Lightly press the floured cup onto the dough ball until it is 1/4" thick. Repeat!
Zesting lemons. When zesting lemons, it is important that you hold the zester steadily while moving the lemon back and forth against the grates. Rotate the lemon when needed. Be careful about your fingers!