1. For a handy 1-page pdf that shows three methods for making flying geese units and has the math formulas for making them any side you want, try this link:
2. QuiltersCache also has instructions and formulas for three methods. There isn't a pdf but the web page prints nicely (on my printer, anyway) as two pages without excessive unnecessary web site stuff. There's also a link on the page for printable paper piecing patterns in four sizes of flying geese.
3. This site shows detailed, step-by-step instructions for making four flying geese units at a time:
no-waste method to make 4 flying geese
4. Mary Hickey has an ingenious way of making multiple flying geese units using Seminole piecing techniques. Great for making borders, sashing or blocks that require lots of flying geese.
5. Here's another video that shows how to make 20 flying geese units using strip-piecing methods. Another great method when you need lots and lots of flying geese.
I haven't tried these super-duper methods yet, but I will when the weather warms up enough for me to work in my sewing shed. Right now, I'm still working in my tiny winter sewing station - one corner of my kitchen table.