RSS feeds are very useful, and indeed, very popular. WordPress creates RSS feeds by default, which is good in 99% of times. But how to create your own, custom RSS Feed? Just read this post to find out!

If you need a custom RSS feed, like for example, a feed indexing only somes categories + tags, or if you redirected all WordPress RSS feeds to Feedburner but still want to be able to get a category feed, the solution is to use a page template.
Simply paste the following code in a new file, save it under the name custom-feed.php and upload it on your theme directory.
Once done, simply write a new page in WordPress Dashboard (Don’t type any text it in), and select custom-feed.php as a page template.

 <?php /* Template Name: Custom Feed */   $numposts = 5;   function yoast_rss_date( $timestamp = null ) {   $timestamp = ($timestamp==null) ? time() : $timestamp;   echo date(DATE_RSS, $timestamp); }   function yoast_rss_text_limit($string, $length, $replacer = '...') {    $string = strip_tags($string);   if(strlen($string) > $length)      return (preg_match('/^(.*)W.*$/', substr($string, 0, $length+1), $matches) ? $matches[1] : substr($string, 0, $length)) . $replacer;      return $string;  }   $posts = query_posts('showposts='.$numposts);   $lastpost = $numposts - 1;   header("Content-Type: application/rss+xml; charset=UTF-8"); echo '<?xml version="1.0"?>'; ?><rss version="2.0"> <channel>   <title>Yoast E-mail Update</title>   <link>http://yoast.com/</link>   <description>The latest blog posts from Yoast.com.</description>   <language>en-us</language>   <pubDate><?php yoast_rss_date( strtotime($ps[$lastpost]->post_date_gmt) ); ?></pubDate>   <lastBuildDate><?php yoast_rss_date( strtotime($ps[$lastpost]->post_date_gmt) ); ?></lastBuildDate>   <managingEditor>joost@yoast.com</managingEditor> <?php foreach ($posts as $post) { ?>   <item>     <title><?php echo get_the_title($post->ID); ?></title>     <link><?php echo get_permalink($post->ID); ?></link>     <description><?php echo '<![CDATA['.yoast_rss_text_limit($post->post_content, 500).'<br/><br/>Keep on reading: <a href="'.get_permalink($post->ID).'">'.get_the_title($post->ID).'</a>'.']]>';  ?></description>     <pubDate><?php yoast_rss_date( strtotime($post->post_date_gmt) ); ?></pubDate>     <guid><?php echo get_permalink($post->ID); ?></guid>   </item> <?php } ?> </channel> </rss> 

Credits goes to Joost de Valk for this awesome recipe!