Dynamic hair works great for horse tails. That is one of the first things I did with it. A lot easier than making a human hairstyle.

StudioVerite used to have a great tutorial on dynamic hair, but the site seems to have gone down. There are pretty good tutorials here:

http://www.perpetualvisions.com/articles-and-graphics/tutorial-poser5-hair.htm

They don't cover styling as well as the StudioVerite one did, though. Use the styling controls, and you should be able to shape the hair into long, smooth curves pretty easily.