Within the exact renormalisation group approach, it is shown that stability
properties of the flow are controlled by the choice for the regulator. Equally,
the convergence of the flow is enhanced for specific optimised choices for the
regularisation. As an illustration, we exemplify our reasoning for 3d scalar
theories at criticality. Implications for other theories are discussed.Comment: 8 pages, 4 figures, uses ActaStyle.cls, invited talk given at RG2002,
March 10-16, 2002, Strba, Slowaki
