Flirting is about confidence, body language, and from my experience about knowing where the line is between being dirty and being funny - and understanding when the point is where you can cross that line. You not only want to portray yourself as confident, but also want to make the other person feel as confident in themselves. Confidence usually equals safety if it's genuine, and when you feel safe with someone you're willing to accept a lot of things being said that you wouldn't with a complete stranger. That isn't to say this character isn't a stranger, but that they've demonstrated themselves sufficiently in this comfort zone to not be a complete one.
Flirting is difficult, and writing flirty dialog even harder. Fortunately, I've been working on this exact problem in my most recent story and would be happy to share some its passages. I think I did pretty good, so feel free to use them as an example. "Well hello there, baby. My name's Chad Chaddington and I'm kind of a big deal. Maybe you've heard of me?" "Oh, Chad Chaddington! Your girth is so turgid!" "Don't I know it, honey suckle. If your vagina is half as pretty as your face then I would be willing to have intercourse with it." "But my parents--" "Shh, muffin top. All across the land parents just don't understand." "Take me now, Chad Chaddington!" And that's how your write compelling, flirty dialog. Take note, amateurs.
Well I have a few things I don't like about myself. One is cosmetic and would cost a small fortune to fix (I love my country but the healthcare system is broken). The other thing is I tend to be highly inappropriate at random moments, and have very non public discussions in public. And that is just the entrance to the rabbit whole. I have to constantly remind myself that I am human, and not the literal Cave Troll. (But hey nothing wrong with brandishing a cutlass and being a 21st century pirate.)
Maybe you should come to Australia. We have a public medicare system which a high amount of medical costs.
Best way would probably be: How would you like to be flirted with? What are some things you wish the person you're attracted to would do or say to you? What would you find attractive? And go with that - chances are someone else out there would agree with you
I also have problems with portraying flirting, mainly because I don't flirt. Might this not result in the writer projecting too much of their personality onto their characters? My issue with this is that the last thing I would want someone I was attracted to do is flirt with me. I don't find it fun, I find it frustrating and would prefer it if they just got to the point. One of my characters is supposed to be very charming and flirtatious... I usually skip over portraying the traits themselves, and just show the results, ie him having success with various women. But this is me running away from the problem rather than solving it, and I'm not sure it would work if the story were told from his perspective.
Then do get straight to the point - nothing wrong with that either. Truth is if you went up to someone and said, "Hey, would love to get your number." Isn't that flirting, really? And when you haven't a clue how to write flirting, just how else do you wanna practice if not by first portraying what you may think is attractive? Isn't that all we really ever write? You write what you think is appropriate in any given situation. Get the flirting down first - and the easiest is to write how you would go about it yourself. When that is no longer an issue, then worry about fleshing out the characters in a more unique, individual way. If you don't wanna risk this in your WIP, then practise with experimental pieces or short stories first. But if you haven't a clue what flirting may even look like, i think it's a little too soon to worry about injecting too much of yourself into the character. Running before walking, so to speak. Another approach, and could be used alongside what i have said already, is to consider why someone would find something attractive. Truth be told, though, i question just how different our characters can really ever be from ourselves anyway.
Your character has an "IDGAF" attitude (I Don't Give A F...) and he's successful with women because he comes on strong, carries himself with authority and confidence and he believes his own bullshit. Sure, he may be cheesy, and he's certainly not the best looking guy around, but he's by far the most FUN, and that's what makes him successful. If he sees something he likes, he goes for it, makes no apologies and if he gets shot down he continues on to the next girl without skipping a beat. He's as outspoken and unapologetic as they come, and he says whatever's on his mind regardless of how inappropriate it may be. He's like a train wreck: you wish you could just ignore him, but he's just so fascinating and unpredictable that you find yourself wanting to know what he will do next! Guys envy him, but would never want to be him. Women want him, but would never want to keep him. I know that guy. He sounds a LOT like me!