We present an overview of the factors affecting soft magnetic properties and giant magnetoimpedance (GMI) effect as well as of post processing tools allowing optimization of magnetic softness and GMI effect of thin amorphous wires. Generally low coercivity and high GMI effect have been observed in as-prepared Co-rich microwires. The magnetoelastic anisotropy is one of the most important parameters that determine the magnetic softness and GMI effect of glass-coated microwires. Annealing at adequate conditions can be very effective for manipulation the magnetic properties of amorphous ferromagnetic glass-coated microwires. After annealing of Co-rich we can observe transformation of inclined hysteresis loops to rectangular and coexistence of fast magnetization switching and GMI effect in the same sample. Using stress-annealing, GMI effect of Co-rich microwires can be increased. We demonstrated that the switching field value of microwires can be tailored by annealing in the range from 4 to 200 A/m. Similarly stress-annealing allows induction of transverse magnetic anisotropy and improvement of magnetic softness and GMI effect in amorphous Fe-rich microwires. On the other hand in Fe-rich FeCuNbSiB microwires after appropriate annealing we observed considerable magnetic softening and GMI effect enhancement. •Trends in optimization of GMI effect in amorphous and nanocrystalline microwires.•Engineering of magnetic properties and GMI effect in as-prepared amorphous microwires.•Magnetic softening of Fe-rich microwires after stress-annealing.•Improvement of GMI effect after stress-annealing of Fe- and Co-rich microwires.•Improvement of GMI effect after nanocrystallization of Fe- -rich microwires.