Most of my websites are not structured as blogs and I needed a way to turn off the RSS and Atom feeds to avoid confusion. Google turns up lots of different approaches to this but the tidiest in my opinion is to modify the theme by adding a few lines to functions.php as follows:

 * Disable Feeds
function disable_our_feeds() {
	wp_die( __('No RSS Feed Available, 
Please visit our
<a href="'. get_bloginfo('url') .'">
</a>.') );

add_action('do_feed', 'disable_our_feeds', 1);
add_action('do_feed_rdf', 'disable_our_feeds', 1);
add_action('do_feed_rss', 'disable_our_feeds', 1);
add_action('do_feed_rss2', 'disable_our_feeds', 1);
add_action('do_feed_atom', 'disable_our_feeds', 1);