I always start with tool safety and use. It is not a lecture as I get them to use the tool(s) to make a little sample. then we join the samples all together and thus form a quilt. They get to do bigger stuff later if they show interest - the skill part comes with practice. I don't get too critical of their efforts but encourage them to make something that will not fall apart. I was 7 when I was machine sewing and I have instructed sensible kids who were younger. They don't get to sew with me if they behave in a dangerous way to themselves or others. They like it better if you don't dominate or do the work for them.