Video interviews: do you look at the camera or at the interviewer's face?

Small question that's been bugging me. In a video interview, if I look at the interviewer's face on screen, on their side it looks like I'm looking down. If I look at the camera, I can't see their reactions at all and it feels like talking to a wall.

What I'm trying now: camera while I'm speaking, their face while they're speaking. It works in practice sessions but I keep forgetting in the middle of a longer answer.

Tricks I've heard: a small sticker next to the camera, shrinking the video window and moving it right under the camera, or just not worrying about it because everyone has the same problem.

What do you do? And does anyone else find it harder to read the interviewer on video, so you don't know when to stop talking?