Yeah, easy mode on her very first client. Look at him, already won over by incredibly basic showmanship and observation skills.

"Left first, then, actually." Which is another bit of conversational finesse to catch him a bit more off guard. This is not going how he expects it, he's now in her power, he's less likely to have time/space to look for how she's doing this when he's fumbling for his footing. Basic conman and/or magician logic.

Once she has it: "I'll be looking at them both, but your non-dominant hand shows your fate untampered. The dominant hand is more what you have made of your fate and your current circumstances. Apparently some others prefer it in the reverse order - looking at where you are before looking at where you started - but I personally find this most cohesive." See, she is not just making this up on her own, she's got references. That totally exist. In another language in an obscure book that isn't in the local library.

This next part is actually based in literally anything. Thank you, Yuki, you maybe got her into this mess with the sketchy ritual that turned out to be real, but you have also given her so much ammunition for her bullshit to sound legit! This may or may not make up for it, she hasn't decided yet.

"This is your heart line," she says, gently tracing the line closest to his fingers. "It shows your emotional and personal life, romantic included." She's not going to say anything in particular about that yet, just watch him out of the corner of her eye for a reaction. (Heh.)

"Okay..." He really doesn't want to get into that, his romantic life is shit. He's just... look, he just hasn't found the right person, okay?

She obligingly moves on without comment, then! (But files his reaction away for later.) On to tracing the next one down.

"This is your - there's not really a perfect translation for it, actually? Mind or head are close, but thought or method also work. It's intellect, thought pattern, decision making, creativity. How you tend to structure your thoughts."