One of the phrases that I overuse like crazy is "I like your face."* I like this phrase. I love that some of my friends have absconded away with it and use it also. You can mean it as is, but it is also a great compliment come-back when you have a loss for ideas, and feel like you can't quite muster the right tone to make an observation seem like a compliment, even though you don't necessarily mean it that way, i.e. "You have a fork in your hair!" Recently I said this to a girl at church.** She said, "aww, thanks. I like your [insert super long pause here] hair." I harbor no ill-will toward this girl, and I'm 80% sure she didn't mean anything by it. I bring this up simply to point out that it seems less like a compliment the longer it takes for you to concoct it. In this instance, probably just an "aww thanks" would have gone a lot further than a compliment come-back.
*Which I have overused for years - way before Bridgit Mendler was ever autotuned.
**"I like your face," not "you have a fork in your hair," although I have absolutely said that before because homegirl*** did have a fork in her hair.
***Fork girl was always super nice, and always showered me in compliments, making me feel awkward that her aesthetic wasn't really something I necessarily appreciated, so "that color looks great on you" (which it did, I wouldn't lie.) was growing a little tired, so I found that if I used the right tone, observations could come off as complimentary. But that can be exhausting, and potentially reinforce things that probably shouldn't be reinforced. Like a fork. In someone's hair.