Bread and Butter: Dubs (2007) is a stock-type double beat exercise that would be well-suited to a high school drumline that is ready to do their homework. Take it slow (slower than the 112 BPM marked… try 80 BPM!) to work on the rhythms, and hey, it turns out that working on doubles that slowly is also very beneficial! It comes from the Bread and Butter packet from the original FatMattDrums website, and I think it has aged well enough to deserve new life here.
Edit 14 November 2021: The link to the pdf was broken, and I have fixed it.