I meet with two guided reading groups a day (I have four in total) and we spend the first 5 minutes or so working on spelling.
With one of my groups we're working on short "o" words. I dictate a word (e.g. soft) and the kids stretch it out, as many times as necessary. When they're ready they print the word in their little spiral-bound notebooks. I've also used chalkboards and white boards, but I like these better. They're easier to manage and store.
I also get them to read the words back to me. That's usually harder for them, but such good practice.
It's super easy to use. It's differentiated. And I feel it really supports my writing program because most of the kids start to feel comfortable writing words with phonetically logical spellings pretty quickly.
I've been working on refining my program the last couple of weeks so that's why I'm sharing this ~ it's been on my mind a lot:) I've made some small changes to my daily spelling routines, but THIS will never change. The McCrackens rock!