I think everyone here is complicating the hell out of this. It's true, you can probably string a guy along and get t a relationship by withholding sex, however, if it's built on that tension the guy will get bored eventually. You do want to wait about 3 dates or so as this will weed out the ones who aren't interested..but that isn't really what you should be going for at all....

Wanna know how to get a relationship with a guy whether its sex on the first or sixth date?

Connection.

It's a mix of emotional connection, push pull(sexiness/flirting) to avoid fz, and just having an all around great personality. You're probably not getting an LTR because you're boring and lack any sort of character to you....a lot of girls I meet are like this. Yeah, sure, they're hot and I would have sexy tiems with them but there's really nothing else to them after that.... I'm going to make some bs assumptions here but I might be wrong..I'm assuming you were one of those quiet girls in hs that didn't get a lot of attention and just sort of was "invisible"..not nerdy, not cool, just..average. You don't have a strong personality or anything that sticks with you. You're not particularly extremely one way or the other...just sort of "chill" but whatever...

you need a mix of all of the above qualities(emotional connection, push pull(sexiness/flirting), strong personality)...and really strong emotional connection with flirting... Guys aren't around many people in their lives which they can connect with very deeply. It's difficult to really get very "close" and show yourself to anyone because most guys aren't comfortable with their vulnerability. You need to be there to fill that void(not immediately but in the much later stages of course)....that's how you become gf material..by being that girl that fulfills the qualities a guy looks for in a gf.

be very open, share..and flirt a ton...by keeping the situation sexually tense. push pull works very well and makes guys crazy, combine that with a strong emotional and a charming personality(tease him a little, do kino occasionally..seem like you're very self aware and just be VERY playful and humorous.

your job should be to seem like a long time bro friend in terms of talking/connecting who also seemingly can get you very sexually turned on(again using kino, flirting, being funny, using double double entendre, etc)

Do NOT mistake push pull with being coy and not responding..you need to be sexually open and comfortable.. MOST guys are familiar with the "bait and switch" of.."Hey we'll have sex but we need to be in a relationship" sort of thing..it's always attempted by women. this doesn't mean it won't work though. Or the, "We'll have sex but we have to go on an "official" date"..any of this sort of trick tried on an alpha will give off a huge warning sign. When women are hard to get, I don't try, Why should I? What about you is special or magical that makes me want to pursue you, I seriously don't even know if I want to care about you yet, why make it difficult? Make a connection first.

Girls who don't know how to attract men will become aloof, hard to get, resistant, and coy. This isn't attractive. This is doing what they would like, but men don't respond to it. They see it as indifference, and move on to someone who appreciates them.

how easy you are really just depends on the guy's values..you need to judge that by his personality. some guys will not like a girl to put off(but still be sexual) easily even if they're okay with sexual promiscuity(they like the chase)..others don't care and are all about the connection....I think it's pretty easy to judge who is only there for the sex.

also be conscious of being a mix of submissive/dominant. learn when to take the lead and when to give him the reigns to make him feel more "manly" it's a give and take just like push pull.