Efforts worldwide to find viable thermoelectrics (TE) are intensifying . We have achieved selective scattering of phonons and thereby critical enhancement of TE properties through nanostructuring: both a) mechanical and b) bottom-up methods. For example, previously, quick, inexpensive, bottom-up wet processes were found to fabricate nanosheets of telluride thermoelectric materials leading to enhanced ZT . We have also recently discovered a bottom-up nanostructuring method leading to a 100% enhancement (i.e. ZT≈1.6) in“empty” rare earth-free skutterudites , and details and possibilities to apply to other materials will be presented. This work is supported by CREST, JST.  Thermoelectric Nanomaterials, ed. K. Koumoto and T. Mori, (Springer, Heidelberg, 2013).  C. Nethravathi et al., J. Mat. Chem. A, 2, 985 (2014).  A. U. Khan et al., submitted.