Exclude personal and local configuration files from version control while ensuring they are properly handled during environment setup. Personal configurations should use patterns like `*.local.*` or be placed in designated directories that are gitignored to prevent accidental commits of developer-specific settings. When setting up new environments or worktrees, be explicit about which configuration files to copy. Use specific patterns rather than wildcards to avoid copying unintended files. Example: ```bash # In .gitignore bin/mprocs*.local.yaml .env.local playground/ # In setup scripts - be specific about what to copy if [[ -f "${main_repo}/.env" ]]; then cp "${main_repo}/.env" "${worktree_path}/" fi # Rather than copying all .env* files indiscriminately ``` This prevents personal development configurations from polluting the shared codebase while ensuring consistent environment setup across different development contexts.