The connective constant µ(G) of a quasi-transitive graph G is the asymptotic growth rate of the number of selfavoiding walks (SAWs) on G from a given starting vertex. We survey several aspects of the relationship between the connective constant and the underlying graph G.• We present upper and lower bounds for µ in terms of the vertex-degree and girth of a transitive graph. • We discuss the question of whether µ ≥ φ for transitive cubic graphs (where φ denotes the golden mean), and we introduce the Fisher transformation for SAWs (that is, the replacement of vertices by triangles). • We present strict inequalities for the connective constants µ(G) of transitive graphs G, as G varies. • As a consequence of the last, the connective constant of a Cayley graph of a finitely generated group decreases strictly when a new relator is added, and increases strictly when a non-trivial group element is declared to be a further generator. • We describe so-called graph height functions within an account of 'bridges' for quasi-transitive graphs, and indicate that the bridge constant equals the connective constant when the graph has a unimodular graph height function.• A partial answer is given to the question of the locality of connective constants, based around the existence of unimodular graph height functions. • Examples are presented of Cayley graphs of finitely presented groups that possess graph height functions (that are, in addition, harmonic and unimodular), and that do not. • The review closes with a brief account of the 'speed' of SAW.