Teaching Sorting

Earlier today I saw a facebook post asking for thoughts on teaching sorting. The question was specifically not about motivations like having the class act out sorts or sort cards but rather about the coding. I've been meaning to write about this since last summer when I attended Owen Astrachan's talk on the same subject. Early in my career when teaching sorting I developed the n^2 sorts as standalone routines just as they're presented in most books but as I gained more experience as a teacher, I changed it up to build the sorts (at least some of them) from existing concepts.