Yeah! I made a thread like this somewhere. I'm not cute either!

I don't usually compliment people on their looks unless 1) I can tell they've put forth special effort or something in particular stands out about them or 2) They are really, really, really, really outstandingly attractive to me.

In that case I typically just stare at them, slack-jawed, drooling and attempt to paw at them.

I typically compliment people's actions. Like if someone who doesn't like public speaking stands up and talks to a crowd and does it well - I'll say so.