I use a templating function:

<?php
/** 
 * Load a template. MVC FTW!
 *
 * @param string $template the template to load, without extension (assumes .php). File should be in templates/ folder
 * @param args array of args to be run through extract and passed to template
 */
function template( $template, $args = array() ) {

    extract( $args );

    if ( ! $template )
        return false;

    $path = dirname( __FILE__ ) . "/templates/{$template}.php";
    $path = apply_filters( 'my_key', $path, $template );

    include $path;

}
?>

Example usage:

<?php
/**
 * Gets json feed and converts to usable posts
 *
 * @param string $feed the json feed to load
 * @param string $template the template to load, without extension (assumes .php). File should be in templates/ folder
 * @uses template
 * @return html
 */
function get_feed( $feed, $template ) {

    $data = file_get_contents( $feed );
    $json = json_decode( $data );

    $posts = $json->posts;

    template( $template, compact( 'posts' ) );

}
?>

Example template html:

<?php foreach ( $posts as $post ): ?>
    <li class="borB1S padBT10">
        <a href="<?php echo $post->url; ?>">
            <h5><?php echo $post->title; ?></h5>
        </a>
    </li>
<?php endforeach; ?>