Tailoring magnetic field and current distributions in superconductor/paramagnet heterostructures represents a prospective route to improve HTS superconductor performance in high-current and high-field applications directed at enhancing the current-carrying capability and the critical fields of such heterostructures as well as reducing their hysteretic alternating current (AC) loss. The talk presents a review of macroscopic electromagnetic properties of planar or curved superconductor strips as well as cylindrical wires in various magnetic environments of different shapes and magnetic permeabilities. Since magnetic shielding is largely a geometrical effect, magnetic surroundings may have either detrimental or advantageous influence on superconductor performance. Particularly, conditioning of magnetic fields permits in special cases existence of overcritical states or drastic reduction of AC loss in thin planar superconductor strips. In the case of cylindrical superconductor wires, magnetic coating allows substantial reduction of magnetic flux penetration into the superconductor due to both the magnetic screening and the enhanced Bean-Livingston barrier at the magnet/superconductor interface, which together reduce AC losses in the superconductor. For these structures, also the magnetic cloaking effect is discussed in weak- and high-field regimes. In the case of a superconducting tubular wire, an external magnetic coating provides a huge reduction of AC losses even for a moderate magnetic permeability of the coating. Exact analytical results and finite-element simulations pave the way for turning the method of conditioning of magnetic fields into applications for practical use.