Smart textiles based on nano-enhanced materials are emerging as key innovations in the technological revolution, merging nanomaterials with traditional fabrics to create multifunctional materials for wearable health monitoring, adaptive clothing, and environmental sensing. Despite rapid advancements, the field lacks a systematic and unified approach to guide the development of these advanced materials. This paper introduces a comprehensive five-layer conceptual framework encompassing: (1) Nanomaterial Foundation, (2) Textile Integration, (3) Wearable Electronics Interface, (4) Application Domain, and (5) Sustainability and Lifecycle. The framework provides an integrated roadmap that connects material design, textile engineering, and electronic functionality. It highlights the integration of nanomaterials such as graphene, MXenes, and metallic nanoparticles with textile platforms to achieve enhanced sensing, energy harvesting, and protective properties. Moreover, it emphasizes key trade-offs between functionality, durability, comfort, and environmental impact. The proposed model aims to guide researchers and industries toward scalable, safe, and sustainable smart textile systems, advancing wearable and environmental monitoring technologies.