(NSFW)What makes a man/woman a good kisser?

Can you pinpoint exactly what makes someone a good kisser? Most people I can only assume do whatever they think is best, without really knowing what they are doing at all. Lightly kissing, then pulling back to look in her eyes, then moving gently forward again to kiss deeper, makes it a bit more romantic for her I think.
My mother was of the opinion that trombone players, of which my dad was one, were the best kissers, but that would imply muscular facial strength is important, and I’ve never found that a girl likes her lips mashed against her teeth…