Drupal Field Collection theming, based on this article: https://fourword.fourkitchens.com/article/better-way-theme-field-collections

field--collection-name.tpl.php

<?php foreach($rows as $row): ?>
 <h3><?php print $row['field_collection_name_title']; ?></h3>
 <?php if ($row['field_collection_name_subtitle']): ?>
  <?php print render($row['field_collection_name_subtitle']['safe_value']); ?>
 <?php endif; ?>
 <?php print render($row['field_collection_name_content']['safe_value']); ?>
<?php endforeach; ?>

template.php

/**
 * Creates a simple text rows array from a field collections, to be used in a
 * field_preprocess function.
 *
 * @param $vars
 *   An array of variables to pass to the theme template.
 *
 * @param $field_name
 *   The name of the field being altered.
 *
 * @param $field_array
 *   Array of fields to be turned into rows in the field collection.
 */

function rows_from_field_collection(&$variables, $field_name, $field_array) {
  $variables['rows'] = array();
  foreach($variables['element']['#items'] as $key => $item) {
    $entity_id = $item['value'];
    $entity = field_collection_item_load($entity_id);
    $wrapper = entity_metadata_wrapper('field_collection_item', $entity);
    $row = array();
    foreach($field_array as $field){
      $row[$field] = $wrapper->$field->value();
    }
    $variables['rows'][] = $row;
  }
 }

/**
 * General preprocess function for field.
 */
function rackspace_preprocess_field(&$variables, $hook) {
  $function = __FUNCTION__ . '__' . $variables['element']['#field_name'];
  if (function_exists($function)) {
    $function($variables, $hook);
  }
  // Field Collection theme hook suggestions
  if ($variables['element']['#field_name'] == 'field_collection_name') {
    $variables['theme_hook_suggestions'][] = 'field__collection_name';

    $field_array = array('field_collection_name_title', 'field_collection_name_subtitle','field_collection_name_content');
    rows_from_field_collection($variables, 'field_collection_name', $field_array);
  }
}