<?php if( function_exists('tribe_the_custom_fields') && tribe_get_custom_fields( get_the_ID() ) ): ?>
  <?php
    //Check to see if there is any value in the field before displaying
    if(!empty(tribe_get_custom_field('Add a ticket link'))) { ?>
        <dd class="event-meta event-meta-custom"><a href="<?php echo tribe_get_custom_field('Add a ticket link'); ?>">Ticket</a></dd>
    <?php } ?>
    <?php if(!empty(tribe_get_custom_field('Add a Youtube video link'))) { ?>
        <dd class="event-meta event-meta-custom"><a href="<?php echo tribe_get_custom_field('Add a Youtube video link'); ?>">Youtube</a></dd>
    <?php } ?>
    <?php if(!empty(tribe_get_custom_field('Add a Soundcloud link'))) { ?>
        <dd class="event-meta event-meta-custom"><a href="<?php echo tribe_get_custom_field('Add a Soundcloud link'); ?>">Soundcloud</a></dd>
    <?php } ?>
    <?php if(!empty(tribe_get_custom_field('Add any other promo link'))) { ?>
        <dd class="event-meta event-meta-custom"><a href="<?php echo tribe_get_custom_field('Add any other promo link'); ?>">Promo link</a></dd>
    <?php } ?>
<?php endif; ?>