Description
function drupy_theme_suggestions_node_alter(array &$suggestions, array $variables, $hook) {
  $elements = $variables['elements'];
  /** @var Node */
  $node = $elements['#node'];
  $cleanTitle = preg_replace('/[^A-Za-z0-9 ]/', '', $node->getTitle());
  $cleanTitle = preg_replace('/ /', '_', $cleanTitle);
  $cleanTitle = strtolower($cleanTitle);
  $suggestions[] = $hook . '__' . $cleanTitle;
}

This adds a new theme template option based on the title of the node. This is obviously not useful as-is, because the existing id-based template should be used instead, but it still works as an example.

If you need to add the suggestion with specific precedence (for example, just above the node.html.twig option), you should add it at a specific index in the $suggestions array. How you determine that index is up to you.