Check out a free material function by Eduardo R. that will allow you to create a very nice Fresnel effect using Schlick’s model. The thing here is that the tool lets you “segment” the effect to apply the effect only to a portion of a mesh. The function also allows you to add a fake rim or back light quickly and it can be useful when it comes to visual effects.
The latest update allows you to use 3 Fresnel functions:
Schlick’s model from the book “The Renderman: Shading Language Guide”