The question I always ask myself is "will she use it?"
I don't usually take anything the first time, but
@Harry H has a good suggestion. Something like berries or chocolate they will probably like and in any case they can always share if they don't eat it themselves.
For regulars who I know drink, I take them some wine. The name and/or picture can be a little warm-up joke: Seduction, Fickle Mistress, etc...
When Michelle was here two years ago, I settled on a particular mid-range wine with a memorable picture. When I saw her at Pillow Talk Petone in January, I took a bottle and both she and Helen remembered sharing bottles together, so that was a win.
Not exactly a gift, but with the Asian girls, especially with the upcoming New Year, get some red envelopes from an Asian supermarket and put the cash in one of those.
Most of all, listen. When I first saw Ruby in December she mentioned she liked dark chocolate, and she kidded about how we were "China Girl, Kiwi Boy" (I'm sure she said that to all the Kiwi boys, but it was still good fun). So, the second (and sadly final) time I visited, I took her some dark chocolate and a Kiwi key ring, which she thought was hilarious.