Craftiness is the noun: the quality of being good at getting what you want by clever planning, and by keeping the plan partly secret. It is the fox’s gift in a children’s story, and also a word for a person who always seems one step ahead — in a way that makes you admire them a little and not quite trust them. It can sound almost playful (“the craftiness of the plan”) or quite unkind, depending on the voice. You would not put it on a school report as praise. Though actually, the pieces are simple and old: take crafty and add -ness, the ending that turns a way of being into a thing you can name (kind → kindness, dark → darkness). The “skill” history is still sitting inside the word, but the living meaning has slid toward trickery. If you mean the honest skill of making things well, that is craftsmanship, not craftiness.