Many effects use a standard lighting rig which uses 3 lights similar to how a movie company would film a movie.
Here is a wiki link: http://en.wikipedia.org/wiki/Three-point_lighting
here is an XNA specific blog about it (concepts can be applied to OpenGL too): http://blogs.msdn.com/b/shawnhar/archive/2007/04/09/the-standard-lighting-rig.aspxLink