In this work epitaxial BiFeO3 (BFO) thin films were grown by pulsed laser deposition on SrTiO3 and REScO3 (RE = Dy, Gd, Sm) substrates, partly covered by a conductive SrRuO3 bottom electrode. The influence of the various boundary condition on the ferroelectric/ferroelastic domain formation in the BFO films was characterized by X-ray diffraction, transmission electron microscopy and piezoresponse force microscopy. Furthermore, the ferroelectric switching behaviour of 71° stripe domains was investigated. The net polarization could be switched stable and reproducible in-plane, however, for out-of-plane switching a transition to a new domain state occurred, which depended on the applied switching frequency. In the last part of the work the differential etching of BFO thin films was studied, which allowed the fabrication of submicron epitaxial structures.