  In this article we develop, step by step, the framework for universal
dynamical control of two-level systems (TLS) or qubits experiencing amplitude-
or phase-noise (AN or PN) due to coupling to a thermal bath. A comprehensive
arsenal of modulation schemes is introduced and applied to either AN or PN,
resulting in completely analogous formulae for the decoherence rates, thus
underscoring the unified nature of this universal formalism. We then address
the extension of this formalism to multipartite decoherence control, where
symmetries are exploited to overcome decoherence.
