Ultracold and quantum degenerate mixtures of two or more atomic species open up many new research avenues, including the formation of ultracold heteronuclear ground-state molecules possessing a permanent electric dipole moment. The anisotropic, long range dipole-dipole interactions between such molecules offer many potential applications, including novel schemes for quantum information processing and simulation. Our goal is to create ultracold ground-state RbCs molecules using magneto-association on a Feshbach resonance followed by optical transfer to the rovibronic ground state. Here we present our recent results on the formation of both ultracold Cs₂ Feshbach molecules from a Cs Bose-Einstein condensate and ultracold ⁸⁷RbCs Feshbach molecules from a Rb-Cs atomic mixture. In the case of the Cs₂ Feshbach molecules we demonstrate the repeated output coupling of molecules from the atomic cloud and, using an avoided crossing in the bound state spectrum, we 'bounce' the molecular cloud in time of flight and engineer 'collisions' between two molecular clouds. For ⁸⁷RbCs we discuss the magneto-association scheme, which is complicated by the large background interspecies scattering length, and outline our progress towards the optical transfer to the ground state using stimulated Raman adiabatic passage (STIRAP).