[ That's a start, Castiel can give him that. And it's not like he's the epitome of successful social interaction. He's not and he knows it. But simply because he doesn't know how to do something properly doesn't prevent Castiel from offering his opinion on it. ]

Logan is your friend, is he not? You take care of him, provide shelter for him and feed him, protect him from harm? Perhaps it would help to show him affection.

[ Not that Castiel's the greatest at doing that either, but he's been on Earth long enough to know that it helps smooth over an individual's dealings with another. ]