  We review theoretical approaches to form factors that arise in heavy-meson
decays and are hadronic expressions of non-perturbative QCD. After motivating
their origin in QCD factorisation, we retrace their evolution from quark-model
calculations to non-perturbative QCD techniques with an emphasis on
formulations of truncated heavy-light amplitudes based upon Dyson-Schwinger
equations. We compare model predictions exemplarily for the B\to\pi transition
form factor and discuss new results for the g_{D*D\pi} coupling in the hadronic
D* decay.
