Change the WordPress New Post title placeholder

wordpress-set-new-post-title-placeholder.php

<?php
// Add this to your theme functions.php file, or in a plugin file
// This example shows how to change the title field placeholder

// Post types titles
function cpm_change_default_title( $title ) {

  $screen = get_current_screen();

  if ( 'product' == $screen->post_type ) { // Change product for your post_type (.e.g post, page, etc)
      $title = "Enter product name";
  }

  return $title;
}
add_filter( 'enter_title_here', 'cpm_change_default_title' );