Sewing

Sure!

I started with a German pattern designer, who posts in depth video tutorials to all her designs, called pattydoo.

Even if you don't speak German, she speaks very clearly so I guess YouTube auto subtitles could do a decent job.

While I'd personally recommend starting on sth easy like a beanie. I think it's more important that you show them why sewing is awesome. And that is because you can use your imagination to do what you want and make it reality. Make a piece of clothing you like in the style/colors/pattern you want. So if they want to go for a t-shirt or dress instead, let them 🙂 (perhaps steer clear from sth really complex like a buttoned shirt for the first thing they make...)

Then take it from there. Let them plan the project themselves (what do I want to do, which cloth do I want, how much do I need, how many buttons etc).

Especially in the beginning be generous with how much cloth you buy, that way they can make mistakes without having to stop for a week, waiting for the next trip to the store to buy an extra half-meter of fabric. And you'll find some use for smaller leftovers eventually.