Creating an optimal CI/CD workflow can be challenging, but dependency caching offers a straightforward way to enhance efficiency by reducing build times in CircleCI pipelines. Dependency caching involves storing frequently used data, such as libraries or packages, in memory to avoid downloading them repeatedly during each build process. This technique significantly speeds up workflows, particularly for projects with numerous dependencies managed by tools like npm, Yarn, or pip. By adding restore_cache and save_cache steps to the config.yml file, developers can efficiently manage dependencies, improving build speed and feedback time. Using unique keys, such as checksums of dependency management files, allows CircleCI to track changes and create new caches when necessary. This dynamic approach ensures that only necessary dependencies are installed, saving time and resources. The guide suggests that dependency caching is just one of many possible optimizations, with additional techniques like persisting data in workspaces and Docker layer caching also available to further streamline CI/CD processes.