Style WP_Debug?

You could add following code (if not done already) in wp-config.php (please make a backup first of this file):

define('WP_DEBUG', true);
define( 'WP_DEBUG_LOG', true );
define( 'WP_DEBUG_DISPLAY', false );

This way debug is activated but the results (if have errors/notices) will not be shown but will be saved in a logfile which you can find then in wp-content folder. THe file which ‘collects’ all is debug.log.

See the Codex for further explanations

Side note: (I know I should not do it but…) you also can look for a plugin (as addon to make it yourself easier during your work) named debug-bar and or others.