Here's the finished sample... now for the directions:
First, the diagram... it's sort of confusing so look over the pictures..
Here are the first 8 stitches formed into a ring then two stitches. Here is where you add the additional thread. I used purple so you could see better.
get your cro-tat hook out and work the scallop on the hook.
The thread is tightened on the hook.
remove the hook and put the tatting needle through the first loop...
Use the ball thread and put 5 stitches on the needle.
now pick up the other end of the scallop onto the needle. Work 2 more stitches.
then use the cro-tat hook again to create another scallop...
Here are two scallops done. Work as many scallops as you want. When you have enough, work 2 stitches with the ball thread then finish off with a circle of 8.
I left the threads so you can see them.