Do you have any advice on ensuring a best possible encounter with penguins?

Yes, there is good advice for making sure you have a perfect penguin encounter.

Penguins are curious. Pick a spot no closer than 5 meters from the penguins. Sit or kneel — making yourself smaller and less threatening. Wait quietly, with your camera ready — they will be much more open to coming over to you than vice versa. Otherwise, you would scare them away.