Get multiple tags by slug

I’ve come up with a better way than in my previous answer:

First you need to set up an array containing the slugs of the tags you want to exclude. Then loop over that array, and on each term, use get_term_by() to get the tag, saving its ID to another array. That is what you can pass through to your query.

$tag_slugs = array(
    'foo',
    'bar',
);

$tag_ids = array();
foreach( $tag_slugs as $slug ) {
    $tag = get_term_by( 'slug', $slug, 'post_tag' );
    $tag_ids[] = $tag->term_id;
}

$args = array ( 
  'posts_per_page' => 5, 
  'paged'          => $paged,
  'post__not_in'   => get_option( 'sticky_posts' ),
  'tag__not_in'    => $tag_ids,
);