I don't believe I've ever really been taught how to tape; I think as students we all just convergently evolved similar techniques to tape each corner down at a diagonal. Then at the end of the painting, you peel it back and extend the artwork into those blank corners if necessary.
As a teacher, I did start to tell my students to aim for a small but not tiny amount of corner coverage: too much and you have more to fix at the end, while too little and the paper pulls free from the tape and falls at inopportune moments. I also tell them that if you want the tape to be sticky-but-not-too-sticky, you can press it to your pants or shirt first for easier removal.
While I was doing my first artist residency at Arts Itoya in Japan in June 2024, I used this same taping technique and it damaged several of the delicate washi papers.
To the right, you can see an image of my in-progress Paper Snow in January 2025 with taped corners.
I innovated a new technique during my second artist residency at Arts Itoya in June 2025! The new method is to place a piece of acid-free archival tape onto the back of the paper. That tape can remain indefinitely if the paper is prone to tearing, or can be gently removed if desired, and even if it does cause slight surface damage upon removal, that's happening on the side of paper no one's seeing. Then I place another piece of tape onto the first and extend it out past the edge of the painting so the sticky side is face up. Then I place a piece of tape sticky side down onto that. Here is an image of this taping technique: