I've read a couple of good MG books lately. Lauren Wolk's WOLF HOLLOW is a powerful book about guilt, responsibility, the rippling effects of malice, and the loss of innocence. The narrator is a woman looking back on events that happened when she was 12, living happily on a farm during WWII. Apparently Wolk wrote it as an adult book and the publisher talked her into releasing the book as middle-grade fiction. Frankly, I found the book so tense that I'd have been traumatized by reading it at, say, age 10. It's extremely well done though. I recommend it.
I also read THE BLACKSTONE KEY by Kevin Sands. It's a middle grade book set during the Restoration, and it's a good read for adults as well as kids. It's interesting to see how some MG and YA books cross over to adults well and some don't. I don't know what the difference is. In this book, an apprentice apothecary and his friend break codes to solve a mystery.
I also read a good YA book, E. M. Kokie's RADICAL, which is about prepper culture. It's in first person, and that can make it hard for a writer to convey details about the MC, who's unlikely to be narrating about themselves. In Chapter 1 of RADICAL, Kokie does a clever thing with that problem. I like clever. It's a timely book, given the growth of the Sovereign Citizen movement and the paranoia that leads a small number of people to amass a large number of guns.
Now I'm reading the new Louise Penny mystery. This series is set in a small town in Quebec and has a wonderful sense of place.
I've been doing what feels like a last round of revision for a new book. I've worked on this on and off for a while so you may have heard me talk about it before. The MC is a 15-year-old boy who's marooned on the streets of a quasi-medieval city. To earn a few pennies, he pretends to be able to tell fortunes. Then he accidentally tells a true fortune for the prince and is taken into the palace to be the royal fortune teller. Good news: food and a warm bed. Bad news: He can't tell fortunes.
Anyway, when I revise, I run into two issues over and over. (1) My enjoyment of humor often leads me to undercut the story's tension with a joke. (2) I have a hard time being mean enough to my characters. Actually, undercutting tension with humor may be part of #2 too. I'm uncomfortable when things get bad. Also I tend to lay out my plot first, and while concentrating on it, I skim over the real emotions a real person would feel in the situation. So I have to go back and think about those and make them clear and real.