I think I will call worksheets "activity sheets" from now on. They aren't meant to be "work". They are simply to get the kids involved and to practice using a writing implement (we use crayons) and to practice circling things, tracing lines, or even practice writing letters or numbers. Since I intend them as activities rather than "work", I'll refer to them as activity sheets from now on.
Sometimes Aaron gets stressed out about tracing letters or numbers and wants me to help him, which I do. I don't want it to be stressful, but I also want him to try things even if he thinks he can't do them. I try to pick pages that I think suit his level. And I praise all his attempts and tell him he doesn't have to finish anything he doesn't want to. But generally he wants to finish the page. He enjoys the challenge. I worry that other kids won't feel the same way, but I try to pick activity sheets that incorporate various levels on one page. For example, circling letters on the top and tracing them on the bottom. Kids who are too young to trace letters can skip that part.