  I verify the existence of left Bousfield localizations and of enriched left
Bousfield localizations, and I prove a collection of useful technical results
characterizing certain fibrations of (enriched) left Bousfield localizations. I
also use such Bousfield localizations to construct a number of new model
categories, including models for the homotopy limit of right Quillen
presheaves, for Postnikov towers in model categories, and for presheaves valued
in a symmetric monoidal model category satisfying a homotopy-coherent descent
condition.
