A great look at creating rigging controls for an eyebrow area of a character from Luiz Philippe Moreira, which will provide lots of control with not a lot of clutter in the rig.
how to setup Eye Brow controls for you character
The idea behind the rig is to give the animator plenty of control and flexibility over the eyebrow without crowding the area with a lot of control objects. Luiz does this by using Curves instead of joints to drive the deformation of the mesh.
Adding a Curves Control Vertex at every polygon vertex in the eyebrow area, binding the geometry to the curve, affecting the skin cluster on a component level. This will allow the deformation to essentially follow the shape of the curve.