Just Take The Compliment and Run
I don't like telling people what to do. Not really my style. But I'm going to tell you what not to do.
This might be a controversial topic, but... Don't respond to a compliment by giving a compliment.
When someone says; "you look beautiful!" Don't say; "you look beautiful too!" Especially if you are dressed to the 9's and they are in sweats and greasy cause they haven't showered in 3 days (yes, beauty isn't just about appearances, we know this, but just pretend we are all shallow for a moment and play along.) In this scenario it's pretty safe to assume that the one who initiated the compliment will feel like you are returning the compliment out of obligation, and they will be right. Even coming up with a different compliment altogether ends in the same result. Don't do it.
Because when you do that...
A. You aren't truly even receiving the compliment and
B. It feels like a discount to the compliment or that you are ignoring or minimizing the compliment which is even worse than not receiving it in the first place!
Just say thank you.
And mean it. Soak it up, man.
Clearly you earned it ;)