Drupal 8 developer friendly settings

development.services.yml

# Local development services.
#
# To activate this feature, follow the instructions at the top of the
# 'example.settings.local.php' file, which sits next to this file.
services:
  cache.backend.null:
    class: Drupal\Core\Cache\NullBackendFactory

services.dev.yml

parameters:
  twig.config:
    debug: true

settings.php

<?php

/**
 * Enable local development services.
 */
$settings['container_yamls'][] = DRUPAL_ROOT . '/sites/development.services.yml';
$settings['container_yamls'][] = DRUPAL_ROOT . '/sites/default/services.dev.yml';

/**
 * Show all error messages, with backtrace information.
 */
$config['system.logging']['error_level'] = 'verbose';

/**
 * Disable CSS and JS aggregation.
 */
$config['system.performance']['css']['preprocess'] = FALSE;
$config['system.performance']['js']['preprocess'] = FALSE;

/**
 * Disable the render cache.
 *
 * This setting disables the render cache by using the Null cache back-end
 * defined by the development.services.yml file above.
 *
 * Do not use this setting until after the site is installed.
 */
$settings['cache']['bins']['render'] = 'cache.backend.null';

/**
 * Enable access to rebuild.php.
 *
 * This setting can be enabled to allow Drupal's php and database cached
 * storage to be cleared via the rebuild.php page. Access to this page can also
 * be gained by generating a query string from rebuild_token_calculator.sh and
 * using these parameters in a request to rebuild.php.
 */
$settings['rebuild_access'] = TRUE;