You know that question your employer makes you ask? ("For here or to go?") It's not meant to be futile chit-chat when you're out of things to talk about with the customer.
If someone insists twice on staying in, that is your cue to leave away unnecessary packaging.
Oh, but serving a donut on a plate and coffee in a mug is more inconvenient for you because it means you have to wash dishes? Well that's too bad, we didn't really go on strike on Friday for the fun of it. We have a global waste problem so handing every guest - even the ones that stay and sit down to eat/drink - paper cups with plastic lining that contribute to this problem is sad. read more