One of the basic techniques is to have a profile photo. This appears in a video conference if the camera is off. I use a still image taken by my web camera showing me dressed typically for a video conference with the usual background. When not speaking in a video conference, I suspect than many people don't notice I switch from live video to the still image.
Teachers express frustration about talking to a Zoom screen showing rows of black rectangles. It is tempting to tell students to turn on their cameras, but there are many reasons they may be unwilling or unable to. I use a wireless broadband connection which sometimes can't support video. Sometimes I am in a shared office with people who do not want to be on camera. So I understand why students do not want to turn a camera on.
On a visit to Cambridge University, some years ago, I came across research which suggested people relate to a computer as if it was human, if it has a face. This did not need to be high quality video, a still image, or even a smile face would do :-)
So I suggest that having students include profile photos on their video would help teachers feel they are talking to people. This could be implemented by asking students, or by having the Learning Management System provide the official student photos to the video conference system by default.