I'm currently creating a bunch of (empty) pages and performing conditionals such as
is_page('Blabla') on it, which increases my page.php significantly. I'm already using
require_once for different content, but is there a cleaner way of doing this?
Wordpress has a function for including template parts, which you can use for that purpose : get_template_part
You can also use
include(TEMPLATEPATH . '/includes/myfunction.php');