  We present a simple scheme for constructing models that achieve successful
gauge mediation of supersymmetry breaking. In addition to our previous work [1]
that proposed drastically simplified models using metastable vacua of
supersymmetry breaking in vector-like theories, we show there are many other
successful models using various types of supersymmetry breaking mechanisms that
rely on enhanced low-energy U(1)_R symmetries. In models where supersymmetry is
broken by elementary singlets, one needs to assume U(1)_R violating effects are
accidentally small, while in models where composite fields break supersymmetry,
emergence of approximate low-energy U(1)_R symmetries can be understood simply
on dimensional grounds. Even though the scheme still requires somewhat small
parameters to sufficiently suppress gravity mediation, we discuss their
possible origins due to dimensional transmutation. The scheme accommodates a
wide range of the gravitino mass to avoid cosmological problems.
