The proposed research focuses on the stability of partitioned coupling schemes for fluid-structure interaction. In particular, the aim is to practically formalize the so-called added-mass effect, which is responsible for the instability of explicit couplings under certain conditions. An expression for the added-mass operator will be given, in a generalized view encompassing the various coupling situations, notably with compressible or incompressible fluids, and incorporating the indispensable consideration of boundary conditions. A generic correction strategy will then be proposed, with the aim of improving coupling stability without resorting to scheme implicitation. Some early implementation details will be discussed, as well as some first results showing the potential and limits of the proposed approach. A second part of the talk will be dedicated to advance grid motion techniques for Arbitrary Lagrange Euler simulations. It will share recent advances in terms of robustness, computational performance and flexibility implementation to make it easy to access in generic purpose CFD software. Some examples with extreme mesh motion will be provided in 2D and 3D.