Start with the sentence this whole programme rests on: you cannot make someone love you. Anything sold as a method for producing desire in a specific person is either useless or manipulative, and usually both. What you can do — reliably, and with practice — is create the conditions in which genuine connection is possible, and then let the other person's real answer be the answer.
So what do people actually respond to? Three things, and none of them are lines. Presence: you are here, in this conversation, rather than performing or scanning the room. Warmth: you are visibly glad to be talking to this person and it costs you nothing to show it. Self-respect: you have a life, standards and opinions of your own, so your interest is a choice rather than a need.
Notice what is missing from that list. Height, income, wit, a rehearsed opener, being 'high value'. Those things influence a first impression at the margins; they have almost no effect on whether someone wants a second conversation. What decides that is how a person felt in your company — specifically, whether they felt interesting, at ease and unpressured.
This is why techniques backfire. Negging, manufactured scarcity, deliberate delays before replying, pretending to be busier or more sought-after than you are: they can generate a flicker of interest, but they build the relationship on a false version of you, and every one of them requires maintaining the lie for as long as the relationship lasts. Also, most adults recognise it, and what they feel isn't intrigue — it's mild contempt.
The reframe for the whole programme: you are not trying to win someone. You are trying to find out, honestly and without pressure, whether there is something mutual here — and to be someone worth finding. That is a much better game, and unlike the other one, you can play it as yourself.