I have been complimenting her profusely on her smile. "You have such a great smile, it really is one of the best things I see all day! It makes me happy inside when you shine those bright teeth at me!" Which of course makes her smile all the larger. Now every morning she says, "Have you seen a smile yet today?" I am not a morning person, but I cannot resist this overture, even at my sleepiest and grumpiest. She holds her hands behind her back and beams her best smile at me. Then we have a good morning hug, which she throws her whole self into.
She has also gotten into the habit of occasionally turning to me or S and saying, "Thanks, dad, for ____." Very genuine, too. We encourage her by responding: "You're welcome, honey, that makes me feel good inside!" She also will occasionally burst out with, "You're the best dad EVER!" Often after I give her a treat, but hey, I'll take the compliments wherever I can get them.