Why they go stale
A one-to-one becomes a status update when the person stops believing that raising something changes anything. That belief is not formed by what you say in the meeting — it is formed by whether the thing they raised last month ever moved.
Every technique for running better one-to-ones is downstream of this. If nothing follows, no agenda helps.
Open with the last one
Start by naming what they raised last time and saying what happened to it, including when the answer is that nothing happened and why. Doing this once changes the next conversation more than any question you could ask.
This requires actually knowing what they said, which is the part people get wrong. Memory is a poor record of a conversation from four weeks ago, and a note written from memory afterwards is a record of what struck you, not of what they said.
Ask fewer, worse-mannered questions
“How are things?” gets “fine”. “What is the most annoying part of your week right now?” gets an answer, because it is specific and because it gives permission to complain.
One good question and a long silence beats a list. The silence is the technique.
Write down what you committed to, not what they said
Most managers leave a one-to-one with notes on the other person's work. The useful record is the opposite: what you said you would find out, fix, or ask someone about.
That list is the entire content of the next meeting's opening.
On recording these
Be careful here. A one-to-one is the meeting where someone is most likely to say something they would not say on a recording — about a colleague, about you, about whether they are staying.
If you record them, say so every time rather than once, and be genuinely relaxed about being asked to stop. If the honest answer is that recording would change what gets said, do not record them. Some rooms are worth keeping unrecorded, and we would rather say that than sell you a device for one.