  We develop a "variational mass" expansion approach, recently introduced in
the Gross--Neveu model, to evaluate some of the order parameters of chiral
symmetry breakdown in QCD. The method relies on a reorganization of the usual
perturbation theory with the addition of an "arbitrary quark mass $m$, whose
non-perturbative behaviour is inferred partly from renormalization group
properties, and from analytic continuation in $m$ properties. The resulting
ansatz can be optimized, and in the chiral limit $m \to 0$ we estimate the
dynamical contribution to the "constituent" masses of the light quarks
$M_{u,d,s}$; the pion decay constant $F_\pi$ and the quark condensate $< \bar q
q >$.
