Even if you mostly use power tools there are still some hand tool skills that you need to master. Chiseling corners neatly is one such skill. If you don’t learn how to do this it will take too long and the results won’t be clean. In this video he cut a large rabbet using a rabbeting bit. That gave him rounded corners. He fixed the corners using a chisel. The steps to achieve a perfect continuation of the rabbeted edge, without mangling the lines, requires quite a bit of attention to detail. He finishes the job with a card scraper which is a nice little tip.