After doing several laps at the trot I took a walk break, then began a trot serpentine when I reached C. I rode several of them before beginning the dressage test I am working on, Intro Test C, riding Chester at the canter for the canter parts. The canter to the left was a little sloppy, so I had to redo it a couple times, but the canter right was much better. There was one time when I was sitting deep in the saddle rather than being bounced up.
I ran through the test twice. The second time was much better: the shapes were more precise and the halting and saluting went much better.
Before putting Chester away I watched another girl, Maddie, ride her gelding Bentley so I could learn something from observing her. She rode some leg yields, shoulder fores, and canter serpentines, with a couple simple changes in between each circle. It's nice to watch someone else ride so you can better visualize what you are supposed to be doing.