Mean-field calculations based on effective forces are among the most microscopic methods which are available for nuclear structure studies at present. In this seminar, focusing on the Skyrme interactions, their capability to describe collective as well as single-particle states will be very briefly reviewed. The impact of the zero-range tensor terms will be discussed both in the static (Hartree-Fock) and time-dependent (RPA) calculations. Finally, we present some first results of a complete self-consistent, second-order framework aimed at describing not only single-particle and vibrational states but also their full coupling