  We describe the form factors for B to rho lepton neutrino and B to K* gamma
decays with just two parameters and the two form factors for B to pi lepton
neutrino with a further two or three parameters. The parametrizations are
consistent with heavy quark symmetry, kinematic constraints and lattice
results, which we use to determine the parameters. In addition, we test
versions of the parametrizations consistent (or not) with light-cone sum rule
scaling relations at q^2=0.
