There are many ways to make a person feel good about themselves, and one of the best is by giving them a lovely and accurate compliment that highlights either a quality they know that people appreciate and secretly feel a little proud of, or that shows them you've noticed something about them that is rarely noted, perhaps even something they didn't think about themselves. A nice and simple way to do this, assuming that person is a dog lover, is to tell them the breed of which they most remind you. You will see their face light up as they conclude that you really, truly see them, and feel deeply validated.
Non-dog people might ask what is so complimentary about being compared to a dumb, hairy, slobbery beast. These people do not understand that for us dog people, dogs are the model of all that is good and decent and snuggly in this world. We measure the loyalty and trustworthiness of a person by how like a Labrador they are; their smarts and playfulness by how like a Collie they are; and their shyness by how like a shelter mutt they are. To say that a person is like one of these is thus a beautiful compliment. So, tell us about yourself, and we'll compliment you by showing you the doggie self you might - if you really were a dog - see (and doubtless, bark at) in the mirror!