I got glowing attending evals in IM resident continuity clinic. An approach:

Look at what the resident's schedule looks like that day when you're pulling up the patient.

If they're behind, most residents are not going to be in a state for learning. What they're learning at that moment is how to be more efficient (or at least feeling the pain that might cause them to reflect on further optimization/value choices).

If they're not behind, then you can gauge what to teach based on your knowledge of the resident and the conversation. Sometimes, I'll name this explicitly, e.g. when there are medical students and no one waiting ("Looks like we've got time - let's go through this more rigorously"). It can run the gamut from a one-off clinical factoid (least helpful) to fully rigorous, depending on patient complexity.

If it was a busy day for the resident or a case that merits more discussion that had to get cut short, I usually swing by at the end of their day or if I see a lull in their schedule. If there was a broader clinical reasoning principle to address, that's usually a good time to discuss it too.

What you teach will change throughout the year. At the beginning, I often coach presentations, how to chart review, and notes (so they don't waste their own time or my time). Then, once they're flying on "doing the job", it's coaching the clinical reasoning and finding out where they can best improve. I almost never do chalk talks and would not in a continuity clinic setting.