I don't think anyone's mentioned yet about writing the word ART on the
board in large letters, and explaining that every time you are
interrupted or aren't getting everyone's attention while you're
conducting class, you will erase one letter. If you have to erase the
T, there's literally and figuratively no more art. It worked well for
the majority of the rowdy classes. For younger students, they would
lose 5-10 minutes of art; the older ones longer or even the rest of the
period. Some teachers write longer words, but I don't like giving
students too many chances. There are always some who will dance right
up to the edge before settling down.