Henry and I have started working on his writing before bedtime. It's a delicate balance because I both want to provide him with individualized attention that helps him make academic progress, but I also don't want to a) teach him something in a different way than he's learning it at school, b) teach him something before he's ready for it (in Montessori, concepts are intentionally very scaffolded and the children move from very concrete experiences to more abstract understanding), c) do too much and end up leaving him overly exhausted (I believe that children do a ton at school and should have ample time to decompress at night), d) squelch his love of learning by making work with me feel tedious, or e) strain our relationship in any way by introducing an unnecessary power dynamic.
Wow, it's even more complicated than I realized!
I address problems A and B through communication with Henry's teacher. I make sure that I'm only working on things that she thinks make sense for Henry.
As for C, D, and E, it's really about observation. I back off whenever I need to. For example, there was a long period of time when Henry didn't want to read at all. I didn't force him. Fortunately, now, he wants to read a BOB book every night before I start reading him a chapter book.
Now that I want to work on writing with him, I'm trying to follow his lead as much as possible. He's very excited about writing out his Christmas list, and he understands that it has to be as legible as possible so that his grandparents understand what he wants! He's very motivated to practice the same letters over and over again to get them right. Right now he's working on the word "drone."
As I'm working with him, I remembered a very helpful strategy from my former teacher days: If you first teach a child how to properly form the letter "c," you unlock a bunch of other letters for them because "c" is the basis of d, g, o, and q. It's five letters for the price of one!