I usually get them wrapped in a thick piece of cardboard, a few inches longer than the book so an impact to the corners of the package doesn't damage the book. It works pretty well.

I know the style you're referring to; that works fine. But I've been getting books delivered in bubble-padded manila envelopes. In one case, I set up a return for the damaged book, explicitly noted that the packaging was inappropriate, was assured the problem would be fixed, and the next three (!) replacement deliveries were also shipped in the stupid manila envelope and, of course, damaged.

They never shipped me an undamaged copy; I gave up after their messaging went from "return the earlier book" to "don't bother; just keep everything".