Judy's Magic Cast On, a-la-Jeny (video demo)

New! as of 6/19 2022, here is a video demonstrating the kinetics of  the method illustrated below. 

A bit over a year ago, I posted my version of Judy's Magic Cast On, which is very similar to the traditional version except that I start on the bottom needle. My original post is here. Then sometime after that, I re-engineered the first step, to make casting on easier and to make the end result neater. In the meantime, I also got some more practice using Adobe Illustrator. So I now present to you some updated illustrations of this excellent provisional cast on brought to you by the extremely clever & creative Judy Becker. In the illustrations below, blue indicates the working yarn, held with the thumb and wrapped over the top needle. Red indicates the tail, held with the forefinger and wrapped over the bottom needle. Starting position:

Position the 2 tips of a circular cable pointing to the left, and wrap the yarn around the bottom needle like so. (This will become your first cast on stitch.) Hold the working yarn with your thumb. Hold the tail with your forefinger. Step 1: Cast on the first top stitch. Bring the working yarn up behind the bottom needle and in front of the top needle.

Now swing your hand down behind the needles, as shown by the arrow. This will bring the working yarn over and around the top needle. The result will look like this. You have now cast on two stitches: one on the bottom needle, and one on the top needle.

Step 2: Cast on the next bottom stitch. Bring the tail up in front of the bottom needle and behind the top needle.

Step 3: Cast on the next top stitch. Bring the working yarn up behind the bottom needle and in front of the top needle, just as you did in Step 1. Swing your hand down behind the needles... ...and you will have two stitches on each needle. Repeat steps 2 and 3 until you have cast on the desired number of stitches. Then you can continue to knit with your working yarn.