Clinch remains one of the least systematically studied phases of Muay Thai competition despite its direct contribution to scoring outcomes in professional bouts. This paper examines the tactical and technical structure of clinch training, identifies the principal drills and methodological approaches used by coaches at different competitive levels, and proposes a periodization framework that integrates clinch work across preparation phases. A systematic literature review of peer-reviewed sources published between 2017 and 2025 was combined with comparative analysis of match-analysis data and existing conditioning models for striking combat sports. The review draws on 20 primary sources indexed in PubMed, Scopus, SportRxiv, and Web of Science. Key findings indicate that clinch engagement accounts for a substantial share of effective scoring actions and that winners of professional bouts demonstrate higher grabbing and evasion rates in decisive rounds. Based on these findings, the paper proposes a three-layer drill taxonomy (technical, tactical, physical) and a four-phase periodization model showing how clinch work should progress from isolated technique toward constrained sparring as competition approaches. The results are of direct practical value for Muay Thai coaches, strength and conditioning specialists, and sports science researchers working with striking combat sport athletes.