In my personal experience I've always found that when I find girls attractive and let them know, they really appreciate it. They can sense that I really appreciate them. Being appreciated feels good.
The point is it's not a tactic. I genuinely find them attractive. Does that mean I'm already invested? Hell no! It's not so important what their reaction to me is, so much as I expressed my truth in the moment. People are usually thankful for something real, it's refreshing.
Example:
Walk in the door, spot a 5'8" brunette HB with a black skirt, red corset that shows off her figure and boobs fantastically, with a large red ruby dotting the front of a black choker that gives her the appearance of a vampire/goth cat. There's a goth theme tonight, and she really went above and beyond. The last time I saw her it was a pirates vs. ninja's theme and she had an amazing ninja outfit. I couldn't keep my eyes off of her and I made sure she noticed.
Ebomb - Wow.. you look fucking hot!
HBninja - Well thank you
Then her friend, the one who runs the dance event, says "I was thinking the same I just didn't actually say it..." kinda meekly. HBninja turns to her and says "Well why the hell not?" playfully and semi-challenging. They start going back and forth with each other for a minute then I say "Haha you girls are amusing. Save me a dance later eh?"
HB gives me the same full body updown I gave her, and then adds in a dramatic pause. She's milking it and enjoying the moment. "Love to. And hey, thanks for having the guts to come right out with it earlier *she smile and me and elbow jabs her friend* "
Me "Anytime *wink*"
and I walk past them both to say hi to more people. I think I told 3-4 women that night some variation of compliment on their looks. A few others I complimented on a particular object of clothing. One girl I told she had "really good energy" and she lit up and told me it made her night.
I like being like that, it makes me feel good, as well as the people around me. From everything I can tell it's a vibe people like.