Effective communication with kittens and cats often involves using a gentle, calm, and consistent tone of voice. High-pitched, soft sounds tend to be more appealing and less threatening to cats. Specific words or phrases themselves are less important than how they are consistently used. For example, saying 'No' firmly but not loudly can help teach boundaries. Using the kitten's name frequently during positive interactions, like feeding or petting, helps them learn to respond. Consistency in the words and tone used for commands or corrections ensures better understanding and response from the cat.