Current mainstream mitigation measures may be insufficient to halt sea-level rise, implying that radical measures may be required. Geoengineering—which can be described as a mechanism to mitigate unprecedented sea-level rise—has garnered scientific interest in line with the present state of climate change. This study investigates traditional and modern geoengineering techniques through a systematic literature review. The results suggest that conventional and pioneering techniques can decrease sea-level rise, and those optimal results would be achieved through the cooperation of methods. Ultimately, findings from this review informed five strategies: tactical application of conventional geoengineering; optimisation through technique alignment; adaptation to receding coastlines; a global platform for project collaboration; and progression of research capabilities. These strategies, in turn, informed a procedural guideline for policymakers who seek to mitigate sea-level rise.