The present invention is generally directed to methods of making diester-based lubricant compositions, wherein formation of diester species proceeds via direct esterification of epoxide intermediates. In some embodiments, the methods for making such diester-based lubricants utilize a biomass precursor and/or low value (e.g., Fischer-Tropsch (FT) olefins and/or alcohols) so as to produce high value diester-based lubricants. In some embodiments, such diester-based lubricants are derived from FT olefins and fatty acids. The fatty acids can be from a bio-based source (i.e., biomass, renewable source) or can be derived from FT alcohols via oxidation.