DOE It Yourself by Mark J. Anderson, A list of Design of Experiments excercizes that can be done in a classroom setting or as home by students with short explanations and links to documents online wtih more details.
Back in the lab, I tackled ink with DOE. I was able to perform a small number of experiments and learn about interactions among the ingredients. I could see which ingredients appeared to be the most important, which ingredients interacted, and which interactions were most important. This really was a powerful technique