Customize WordPress posts written by particular authors
Sometimes you may need to display custom information or in any way change a post, if it is written by a particular author. WordPress reference pages are not that helpful here, rather confusing, yet there is a simple way to do it. Just open the conditional
<?php if($post->post_author == '2'): ?>
Continue with whatever author-specific content you’d like, such as displaying a link to this author’s archives
More by <?php the_author_posts_link(); ?>
And finally close the conditional
<?php endif; ?>
Don’t forget to replace number ‘2’ above with the ID of your author.