Hi Rachel,
Flourishing is one of those elusive things that takes time, patience, and study. But once you learn how it works, it is less complicated than it appears. It is done using a series of strokes to create the final flourish. Once you learn those strokes, you can then use them to flourish things such as animals, etc. There are a few resources that are helpful but the best thing, if at all possible, is to take a class. And then just practice, practice, practice.
IAMPETH offered classes in this in the past. Otherwise, I'm not sure of any other classes.
There are a few free resources. You can learn a lot by studying the old texts. Old books here at IAMPETH -
Everything Offhand Flourishing And some Dover publications:
The prices are ridiculous for this one:
I hope that helps.