In my short 20 years of life, nothing stands out to me more than someone who can't seem to get a grip on reality. The prime example of this is a 21st-century man who still has his head in the dirt thinking that any form of catcalling can actually end successfully. It doesn't really matter if you do it because you have no social sense, think "ah why not!" or find yourself hilarious.. In the grand scheme of things, it just makes you a pretty sucky person.
Don't be that guy. No one wants a guy who sucks.
1. Grab her ass
From first hand experience, when a guy does this randomly at a club or bar, it really does have a 100% success rate of making him the worst human in the entire world. It should also come with a guaranteed knee to the balls.
2. Whistling
This signifies that you are loud, proud and in charge. She has no choice but to cave and marry you on the spot. Why use words like a civilized human when you can remind her of her high school soccer coach during preseason?
3. Noticeably looking her up and down as she walks by
Especially when it's followed by a creepy trying-to-be seductive face that looks like you're trying to hold in a shit. I don't know any girl who doesn't go weak in the knees for this.