Tian Yingzhang's running script is actually good, and the calligraphy teacher in our school also recommended us to use Tian Yingzhang's copybook. I remember that our copybook contains regular script and running script written by 100 Tian Yingzhang. We can practice together. Regular script is the basis of running script. Since you wrote Tian Yingzhang's handwriting, you can practice regular script and running script together.
I hope it works for you. In fact, I practiced his calligraphy for a while, and then I wrote my own. You can also try to write brush strokes. The writing brush is also quite good, and writing brush is good.