Just give a quick "oh, thank you" in a pleasant, surprised tone. Comes off as gracious, but not conceited. Unless it's something you can't help, then it's more charming if you act like it's a skill in a cheeky way. I.e "wow you're tall"
"Thanks I've been working on it"
It's worth noting, you'll come off as more awkward if you try to fire back a compliment yourself. It came organically to them, and isn't necessary to mirror, unless you feel like they're fishing.
Just don’t make a big deal about it. A simple ‘Thanks’, or, if you’re feeling really strongly about it, ‘Thanks so much’. That’s it, don’t go anywhere else with it or call it out with some special recognition. Unless it’s sexual favors, that’s cool too.
This, but even that can become weird some how. I have a friend who sometimes said I was handsome and I replied with a "thank you" every time, but one time did my friend feel it was enough and told me off by saying "you only say thanks!" I was unsure what to answer and said "well I don't believe it but I am thankful for you to think so" never got a "you are handsome" ever again after that xD