$custom_taxterms = wp_get_object_terms($post->ID, array ('klockor','smycken'), array('fields' => 'ids') );
// arguments
$args = array(
'post_type' => 'varumarken',
'post_status' => 'publish',
'posts_per_page' => 5, // you may edit this number
'orderby' => 'rand',
'tax_query' => array(
    'relation' => 'OR',
    array(
        'taxonomy' => 'klockor',
        'field' => 'id',
        'terms' => $custom_taxterms
    ),
    array(
        'taxonomy' => 'smycken',
        'field' => 'id',
        'terms' => $custom_taxterms
    )

),
'post__not_in' => array ($post->ID),
);

$related_items = new WP_Query( $args );
if ( $related_items->have_posts() ) :
    while ( $related_items->have_posts() ) : $related_items->the_post();
        // post stuff here
    endwhile;
endif;
wp_reset_postdata();