Sorry to keep bumping this up, but I really do recommend that book, here it is again in case it got lost on the other page. Her directions are wonderful and the mathematics are awesome. Been thinking of getting my own copy and some are quite affordable! Even though I know how to do partial seams, it's hard for me to figure out how big the rectangles should be. The answer is usually wider and longer than my first attempts without using directions.
Twist & Turn by Sharon Squire Craig.
https://www.amazon.com/Twist-Turn-Fr.../dp/1885588100