How do I debug 404 errors when using a specific static site generator like Jekyll?

For Jekyll, start by checking your `_site` directory to see if the expected files are actually present. Then, inspect your layouts (`_layouts/*.html`) and templates (`*.html`) for any incorrect links or file paths. Run `jekyll build` locally to ensure your site builds correctly and identify any errors. Use the `--debug` flag with `jekyll serve` for more detailed error messages.