Nanocrystalline materials based on titanium dioxide possess unique properties, including photocatalytic and antibacterial activities. Despite many approaches have already been utilized to fabricate and characterize pure and doped TiO₂, a systematic description of its nanostructured samples depending on the synthesis method has not been presented yet. In this study, we shed new light on the process–structure relationships of nanocrystalline TiO₂-based powders fabricated by extraction–pyrolytic, hydrothermal, and sol–gel techniques. The comprehensive analysis of the fabricated nanocrystalline TiO₂-based powders with different anatase/rutile phase content is performed by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The hydrothermal and sol–gel methods are also used to grow TiO₂ particles doped with Cu and Er-Yb. The correlation between synthesis parameters (pyrolysis and annealing temperature) and properties of the produced materials is studied. Particular attention is paid to Raman spectroscopy and the detailed comparison of our obtained data with existing experimental and theoretical studies.