Curse of Strahd (5e) has one page on the "Marks of Horror" (pg7) and how to run that as a GM. It gives a broad strokes overview on what makes things scary and tense. Not very useful from a mechanical standpoint, but very informative for styling your GMing and making the things you hand out a little more impactful. Definitely recommend checking it out!

Link to the page (from my phone, sorry if this doesn't work on desktop): https://online.anyflip.com/afgs/lazb/mobile/index.html#p=8