Thank you, that's very kind of you!
I really appreciate you noticing that.
Thanks. I'm glad I can help you!
Oh, it's nothing! You are flattering me/I'm flattered.
Thank you, but there is still room for improvement.
Thanks! Tom also worked on it. He gave me a lot of help too.
Oh, thanks very much. You look nice too. I like your shirt.
Thank you for saying so, you are such a sweet-talker!
What are you after/What do you want?
Flattery will get you nowhere.