Sanjoy Mahajan and his work with Street Fighting Math (a course at MIT) is one of the primary drivers for embedding this material in this physics class. In 2014 he published this ebook (Creative Common by-nc-sa 4.0 license) which is a deep dive into his thinking. Working your way through this book will pay huge dividends to the brave souls who take it on.
The Art of Insight in Science and Engineering: Mastering Complexity by Sanjoy Mahajan
Sanjoy learned some of these skills in a class on Order of Magnitude phyics that was developed at CalTech. Here is a pdf document of the sorts of problems they addressed.
It seemed like it might be helpful to offer an example of this sort of estimation. I have attached an example of the estimation of the number of grains of sand on all the beaches of the world compared to Avogadro's number.
