Working on a new set of horns/hair for Elder Titan in collab with BladeOfEvilsBane Polypaint and sculpt of hair complete, horns to go! EDIT: And finished the polypaint :)
To fix seams, you can sample colors closest to the seam in photoshop and paint over the edges on your maps, or import your mesh into zbrush, subdivide, drop in your texture, polypaint over the seam, export, and bake the polypaint in xnormal.
With dotas style it is super simple to polypaint hair with just a standard brush and claytubes, maybe modified some to your tastes. Vlad has this CM hat that has some nice hair polypaint shots http://www.workshophatemachine.com/2013/09/30/cm-shapka-making/