There is an ongoing effort to quantify entanglement of quantum pure states for systems with more than two subsystems. In this paper, we consider three general approaches to this problem for three-qubit states: choosing a basis which puts the state into a standard form, enumerating ``local invariants'' (functions of the state which are invariant under local unitary transformations), and using operational quantities such as the number of maximally entangled states which can be distilled. We build on earlier work to extend these three approaches and describe relationships among them.