Today I spent all day doing just that! I did so by making LOTS of figures. I tried to think of several ways to do what I wanted, then choose which was the best for the question I was asking. Of course, I messed up and had to reorganize so many times that the number of figures I created and their level of detail soon became overwhelming! I want to share them with you so you can have a glimpse at how hard my brain has been working. They are approximately in the order in which I created them. The last red and blue one is all I'm going to do for today. The rest are updates from later on when I needed to plan a design not using pH as an independent variable; instead, I use average site mussel shell thickness.
Please don't try to understand them all! Just appreciate them as part of the process of experimental design.