  We present results of modelling Ginga data of a number of Soft X-ray
Transient sources performed with the aim of constraining the geometry of
accretion during various stages of the sources' evolution. Assuming a generic
geometry of a central, extended X-ray source with an external, optically thick
accretion disk, we use consistent models of X-ray reprocessing to constrain the
inner radius of the accretion disk and its ionization state. We show that the
evolution of GS 1124-68 (Nova Muscae 1991) and GS 2000+25 agree qualitatively
with the recent ideas linking the high/low state transition with changing the
inner radius of the optically thick disk, but the case of GS 2023+33 (V404 Cyg)
poses a problem for any model.
