Mesh (high poly) eyebrows as an alternative to (low poly) textured. Instead of using Blender particle eyebrows I decided to make them as mesh to be reusable through MakeHuman. Each hair is non-manifold triangular and goes about 1 mm into the head to avoid visible gaps when posing. Same eyebrows can look awful on some characters and better on other. No texture is needed but they are UV-unwrapped with the roots at the bottom. If you want them darker at the roots and lighter at the tips you can make a BW gradient texture as color mix factor. The preview render is on a default neutral character, using subsurf x1 and a simple cycles material.
CC0 - Creative Commons Zero