  In this article, we address the solution of advection-dominated flow problems
by stabilised methods, by means of least-squares computed stabilised
coefficients. As main methodological tool, we introduce a data-driven
off-line/on-line strategy to compute them with low computational cost.
  We compare the errors provided by the least-squares stabilised coefficients
to those provided by several previously established stabilised coefficients
within the solution of advection-diffusion and Navier-Stokes flows, on
structured and un-structured grids, with and Lagrange Finite Elements up to
third degree of interpolation. In all tested flows the least-squares stabilised
coefficients provide quasi-optimal errors.
  We conclude that the least-squares procedure is a rewarding procedure, worth
to be applied to general stabilised solutions of general flow problems.
