How to tell a good diamond?

How can one distinguish a high-quality diamond from a lesser one? Are there specific factors or techniques that can help identify a truly exceptional diamond? What should one look for when evaluating the clarity, color, cut, and carat weight of a diamond to ensure that it meets the standards of a good diamond? Can you provide any insights or advice on how to navigate the world of diamond buying and ensure that you're getting a genuine, top-quality stone?