  Using a gauge invariant exact renormalization group, we show how to compute
the effective action, and extract the physics, whilst manifestly preserving
gauge invariance at each and every step. As an example we give an elegant
computation of the one-loop SU(N) Yang-Mills beta function, for the first time
at finite N without any gauge fixing or ghosts. It is also completely
independent of the details put in by hand, e.g. the choice of covariantisation
and the cutoff profile, and, therefore, guides us to a procedure for
streamlined calculations.
