I took a course once in flirting. Really. I was alone and realized I must be doing it wrong.

I actually paid a self-described expert and author on the subject to tell me to get a dog, wear an unusual hat and feign interest in what men say. Also smile.

The smiling part seemed like a good pre-emptive strike against guys who think they are flirting when they say, "How 'bout a smile?" If I am scowling or look sad, it's not because I am vacantly waiting for some hearty lothario to invite me to smile. I'm not an emotional jukebox.

Needing lessons in flirting sounds pretty lame on the face of it, like needing to be told how to wash yourself or when to lie socially -- no one has dinner at a friend's house and says, "Thanks for nothing, Mabel! I've never had such undercooked ribs! When I get trichinosis, I'll be sure to hurl in your mailbox!"

And yet, sales of books with titles like "How To Pick Up Super Hot Chicks And Have Your Way With Them" (for men) or "How To Enchant, Rope, Tie, Brand And Marry The Man Of Your Dreams" (for women) have been embarrassingly brisk for decades.

I was talking with a guy who considers himself a fairly smooth operator (I won't name names, because his mother reads my column), and he was incredulous at the true stories of botched flirtation I recounted. Some had happened to me, some had happened to other women I know, and all of them made his jaw drop.

"You should write about this," he said. As a kind of public service. So here is my crash course for guys on How Not To Flirt. You're welcome.

1. Disagree, argue and/or pick a fight. If you tell her she's wrong after less than 30 seconds of conversation, she'll be able to imagine what a date with you would be like. It will be like a date with her previous boyfriend, just before she threw his cell phone off a bridge.

2. Express disappointment. If you've corresponded online or talked on the phone and decide to meet in person, don't blurt out some fatuous comment about how she differs from the ideal woman you would have built in your basement. For example, "You're dressed like a Mormon" or "I thought you'd be blonder."

3. Emphasize your differences. I never cease to marvel at the number of guys who seem to think it's sexy to point out that you have nothing in common. She has a degree in literature and you have to force yourself to read TV listings? She belongs to the Sierra Club and you want to show her your coal-to-PCBs plant? She's a vampire and you're a vegan? Opposites attract, but so does a black hole.

4. Unpad your resume. Whether you did time or your family has a history of insanity, by sharing the goriest of your personal details before love gives her beer goggles, you're doing her a favor. Very selfless; you're not doing yourself one.

5. Invade her space. A poorly spelled, all-capitals note on her windshield doesn't say "impulsive romantic." It says "creepy stalker." And consider this: I once tried to discourage a bar ogler by slipping off my college ring and putting it on my left ring finger with the plain gold band facing out.

"Excuse me," The Ogler suddenly blurted at me, "You weren't wearing that before."

He then asked me if I'd grown up on a farm. He was that slick.

To review: He thought I would want to cozy up to him because he had (a) foiled my attempt to get rid of him, and (b) implied that I reminded him of livestock. I'll be honest: The only thing that gets me hotter than having my obvious escape plan foiled is evidence that a guy is too manly to tolerate a muffler on his car.

I know there are women who flirt poorly too. Heck, I used to be one of them.

But that was before I learned the power of the unusual hat. Now how 'bout a smile?