For starters, don't tell him he's a terrible kisser, even if he is. Just tell him how you like to be kissed.
Every new relationship has a learning curve. We have to get used to the other person's habits, quirks, flaws. We also have to tell them how we like to be touched, kissed, sexed. There's nothing wrong with speaking up and asking for what you want. Better yet, show him.
Instruction is communication, and communication is almost never a bad thing in a relationship. As long as you approach it tactfully (avoid comments like, "Ugh! You kiss like my uncle!") and present it in terms of what you prefer rather than what he's doing wrong, he has no reason to get his feelings hurt.
If he does, it doesn't bode well for your relationship. You have to be able to be honest with each other and express preferences without being hurt. What happens when you're in bed together and you try to tell him how you like to be touched? He has to have the confidence to not be threatened by instruction or see it as disapproval. He needs to be assertive enough to tell you want he wants, too. If he can't, I'd take a step back and give the relationship some serious thought before you proceed.
Teach him well, and practice a lot! :-)
Ask him to kiss you like a romantic scene from one of your favorite movies,role play, what girl doesnt wanna be kissed lke that? (unless your talking about the scene from 'Not Another Teen Movie' where the girl kisses the old lady...ugh gross!)
I always pulled back just a little and whispered in their ears "hold still, I want to show you something...dont move!" And then I kissed them, slowly, amplifying each second, until they started kissing me back. If they started too fast, I would whisper "slowly" and continue kissing them, they eventually got the slow part right and I would speed it up a little and get more involved, then I would whisper "what did you think?" the responses were never bad : )
it can be done!
I was always a perfect kisser so I have nothing to add here...
Ahem... now that the BS is out of the way
"I really liked the way you did... " or "The other day when you kissed me like XYZ I really liked"
And, of course, what the other folks here said I think is great
Easy peasy, whenever he is doing something you don't like, give him a purple nurple. A good "What? You don't like that? Well neither do I!" would be the correct response for his shock and horror. Over a span of time you should notice a significant difference in his kissing style. ;)
Great advice Cary! Give it some time, practice and a little directional information, the issue should resolve itself.