A generic approach to efficient visible light generation based on singly-resonant sum-frequency mixing of an external-cavity tapered diode laser and a diode pumped solid-state laser is presented. The principle is exemplified by generation of more than 300 mW of 488 nm coherent blue light by mixing of a 950 mW beam from an external-cavity 765 nm tapered diode laser with the intra-cavity field of a diode pumped, high finesse 1342 nm solid-state laser using periodically poled KTP as the nonlinear medium. Using this approach, a conversion efficiency of more than 30 % of the 765 nm beam was obtained.