Covariant technique of derivative expansion of the one-loop effective action

A simple systematic method for calculating derivative expansions of the one-loop effective action is presented. This method is based on using symbols of operators and well known deformation quantization theory. To demonstrate its advantages we present several examples of application for scalar theory, Yang-Mills theory, and scalar electrodynamics. The superspace formulation of the method is considered for K\"ahlerian and non-K\"ahlerian quantum corrections for Wess-Zumino and for Heisenberg-Euler Lagrangians in super QED models.