On wide band gap oxides, metal atoms show a tendency to cluster in 3D particles. Since this appears to be unfavourable in many advanced technologies which involve metal/oxide interfaces, improving the wetting at these interfaces is a constant challenge. The present paper focuses on some important means that are stressed to strengthen the interfacial bonding, namely the hydroxylation of the oxide surfaces and the pre-deposition of a buffer. The analysis combines the examination of the interfacial metal/oxide chemistry by photoemission and the characterization of the wetting by UV-visible surface differential reflectivity. This technique is shown to be very appropriate for the in situ study of growing films.