The size, size distribution and shape of ferroelectric BaTiO3 nanoparticles were determined using three different imaging techniques. The nanoparticles fabricated by milling microcrystals were found to have sizes of 12 +/- 3nm, 15 +/- 3nm and 18 +/- 3nm. Liquid crystal suspensions with 1% concentration of nanoparticles were prepared and their dielectric and optical anisotropy were measured. It is shown that the largest particles lead to the strongest enhancement of dielectric and optical anisotropy, as compared with undoped liquid crystals.