There has recently been great interest in growth by molecular beam epitaxy of GaAs films on non-(001) oriented GaAs substrates. This has occurred largely because of the possibility of fabricating novel device structures such as quantum wires and quantum boxes using patterned substrates, However, the growth of high quality lattice matched and mismatched structures on non-(001) GaAs substrates has had a reputation amongst many researchers of being 'difficult'. Epitaxial layers grown on these surfaces have generally had poor surface morphology, bad crystalline quality and irreproducible dopant incorporation behaviour. In this paper we will show that the growth of these materials is not 'difficult', but 'different' and that provided suitable growth conditions are used then high quality layers may be deposited on all substrate orientations, As an illustration we will use reflection high energy electron diffraction to predict the conditions for high quality growth GaAs on the GaAs(111)A. We will then extend this to the mismatched (InGa)As:GaAs(111)A system.