So my local supermarket seems like good pickings.. and there's a few girls who work there that often smile and even wave at me. I've talked to 2 of them a little bit. 1 of them I've definitely caught checking me out. The trouble is I'm stumped as to what I can achieve in the short time it takes for them to ring up my groceries (I don't buy much each day). Any general tips on this?

I feel like there's nothing I can say that leads quickly enough to getting a number, so I've sort of got to play a very long game here until I've gradually chatted them up for weeks? That's a lot of effort. Otherwise, I've got time for about 2 sentences.

Also one of them may be too young but I don't know how to tell. She is definitely a little bit keen, said hi and waved as she disappeared into the break room today.

The first one I might be able to just go 'hey this is random but do you want to go for coffee', but as a general strategy?