I had the opportunity over the weekend to show a 9-year-old girl how to knit. Her mother asked me to teach her while at a picnic, so it was very spur-of-the-moment. While I've wanted to teach someone else, I've never actually had the opportunity before, so I had to think quickly about the best approach to take. I opted to cast on 20 stitches and then showed her how to do the knit stitch. After a few stitches done in super-slow motion, I handed everything over to her so she could try. We broke it down into four steps:
1. Put the right needle through the first loop on the left needle to form an X.
2. Loop the yarn over.
3. Pull the right needle back through the loop.
4. Slip the loop off the left needle.
I had her say each number as she did the step as a way to ensure she did all four steps, since she tended to forget step 4. She made it through the first row, then took a break for a snack, then came back to do a second row. She was so proud of her work and wanted to show everyone!
As an experienced knitter, it was interesting to watch her. We did not deal with tension or "proper" ways to hold needles and yarn. I simply wanted her to learn how to make the stitch without overloading her. Her tension remained extremely loose throughout her two rows, but she started to hold the needles more naturally all on her own toward the end.
I learned to knit when I was about her age, but I have no recollection of how I was taught or how long it took me to have a consistent gauge, so this first time of teaching was all trial and error.
Her mother emailed me yesterday to say that her daughter was working on the knitting during church on Sunday and somehow messed up. Before my friend was able to stop her, her daughter had ripped out all the stitches!

Hopefully, we can get together again, as this little girl really seemed to enjoy learning.