Welcome to this short Quick Tip. This tutorial will show you how to create a parent constraint to a hair follicle. You might think you could just use the normal parents constraints but no. Constraining to a hair follicle enables you to link objects together after they have been deformed. For instance you have a facial rig, and you have plaster covering a scar on the cheek, you want to contrain the plaster to the skin of your character but its just not sticking correctly using simple constraints.
With this neat trick you will be able to connect to objects on surface level, so no shifting of meshes is possible.