Different situations call for different reactions I have experienced being told that I'm being admired and I almost always react the same way: smiling at them (and unconsciously on the verge of blushing) and thanking them. Then to avoid things to be awkward, I compliment them in a harmless way (by definition, no flirting intended) and try to engage a conversation with them whether or not I admire them back. As for the staring.. I don't mind it too. In my opinion it's the most subtle way to express the admiration or attraction you feel towards a person. Aaaand, it gives really good giddy feelings when you catch someone giving you an admiring stare besides, I stare too. One time I walked into our cafeteria and there were a lot of people (duh) and I caught this girl from the lower year staring at me. I tried to smile at her but she looked away. That happened again a few days after and I got to smile at her before she could look away. She smiled back and it actually felt good. I'm a sucker for acknowledgments and simple things like this make me happy. Okay unless the girl doesn't know personal boundaries and how to respect privacy. Then i'm gunna tell her off in the most polite way i could think of.