Owners and managers: what actually decides a trial shift for you?

Every week I read applications from baristas who got a trial shift and never heard back, and I read job posts from owners who ran three trials and hired nobody. Both sides think the other is being unreasonable. So this thread is for the hiring side, and applicants will read it.

If you own or manage a café, roastery or bar, tell us how a trial actually works for you:

• How long is it, and do you pay for it? (In some countries an unpaid trial is illegal past an hour or two. Say what you do, not what the law says.)
• What are you actually watching? Speed, dialling in, how they talk to a regular, whether they wipe the steam wand without being asked?
• What ends a trial early, and what makes you offer the job on the spot?
• How many trials do you run per hire, and how soon do you tell people either way?
• What would you tell a nervous 22-year-old walking in for their first one?

I will start: when I hired, I cared about one thing more than latte art, and it was whether the person noticed what needed doing before I said it. Everything else can be taught in a month.

Write as much or as little as you like. Your name and company show next to the answer, which is also the cheapest recruiting you will do this year.