This is the way I do Josephine or "Spiral" chains and I thought I would share it. It is very simple and the results are very nice. The books I have read state that you should use the first half of the double stitch over and over to create the chain. I prefer to use the second half of the double stitch and I drop the shuttle every 5 stitches to make a nice uniform twist.
As you can see in this first photo. I used my method for the first 15 stitches or so then I did the middle section of 20 stitches where I did NOT drop the shuttle. As you can see, the stitches are all bunched up and are not very attractive. I then resumed using my tatting method.
This photo shows the location where I drop the shuttle every five stitches. I then pick up the shuttle and resume the process.
Finally, this photo is an example of what I would consider to be a good Josephine treatment.
I think a lot of people shy away from using this simple stitch because if done improperly it doesn't look very attractive. But now you know a simple little trick to make it look really nice.
Side note: Josephine chains are done by (encapsulation, reverse tatting, unflipped stitch). These are some of the different names used for the same method.