No special skills are required. All you need are good ingredients, a few basic tools, and a little know-how. It also helps to have the weather on your side. Cookies are little sponges-they absorb moisture from the atmosphere. On a hot, humid day they can turn from crispy-crunchy to soft and limp within hours.
Inconsistency is the bane of a baker's reputation.
They know their dough. If it needs less liquid on a given day, they hold back. My great aunts never measured. The recipe was in their heads and in their hands. Most cookie recipes will work perfectly when baked in temperate zones from September through mid-June, no matter what the weather.