In your php-fpm.conf the most important values are:

error_log = /var/log/php/fpm-errors.log
daemonize = yes

And in your php.ini:

# The most important values:

# Security related
expose_php = Off

# Execution time & memory related
max_execution_time = 30
max_input_time = 60
memory_limit = 128M

# Log related
log_errors = On
error_log = /var/log/php/errors.log

# Upload related
post_max_size = 128M
upload_max_filesize = 64M
max_file_uploads = 10

# Use correct timezone by default
date.timezone = Europe/Berlin

# use strict mode for sessions
session.use_strict_mode = 1


# =========================================
# Production settings
# =========================================
realpath_cache_size = 4M
realpath_cache_ttl = 600

[opcache]
opcache.enable=1
opcache.memory_consumption=256M
opcache.interned_strings_buffer=24
opcache.max_accelerated_files=25000
opcache.use_cwd=0
opcache.validate_timestamps=0
opcache.revalidate_path=0
opcache.save_comments=1
opcache.enable_file_override=1
opcache.consistency_checks=0

Pool Config

For servers with a single projects.

The most important settings are:

[example.org]

user = example_org # Use project user + group
group = example_org

listen = 127.0.0.1:9100 # number consecutively
listen.allowed_clients = 127.0.0.1

pm = ondemand
pm.max_children = 5
pm.start_servers = 2
pm.min_spare_servers = 1
pm.max_spare_servers = 3

pm.process_idle_timeout = 10s
pm.max_requests = 500

catch_workers_output = yes

php_admin_value[error_log] = /var/log/php/$pool-errors.log
php_admin_flag[log_errors] = on

Pool Config (shared server)

For servers with a single project.

The most important settings are:

[example-org]

user = www-data
group = www-data

listen = 127.0.0.1:9100  # number consecutively
listen.allowed_clients = 127.0.0.1

pm = dynamic
pm.max_children = 5
pm.start_servers = 2
pm.min_spare_servers = 1
pm.max_spare_servers = 3

pm.process_idle_timeout = 10s
pm.max_requests = 500

catch_workers_output = yes

php_admin_value[error_log] = /var/log/php/$pool-errors.log
php_admin_flag[log_errors] = on

Photo credit: Ray Zhou