The ability to fabricate nanophotonic metasurfaces with precise structural control, scalable fabrication, and tunable optoelectronic properties is central to advancing next-generation sensing, energy, and spectroscopy applications. Recent breakthroughs in template-assisted self-assembly (TASA) enable the bottom-up fabrication of high-quality and defect-free metasurfaces by using pre-synthesized nanoparticles, responsive polymer matrices, and tailored templates. This approach minimizes material waste, reduces energy consumption, and integrates top-down lithographic precision with bottom-up self-organization, achieving large-area patterning with nanoscale precision [1].