Look at /etc/systemd/system/multi-user.target.wants for some examples.

https://www.digitalocean.com/community/tutorials/how-to-configure-a-linux-service-to-start-automatically-after-a-crash-or-reboot-part-1-practical-examples
https://www.digitalocean.com/community/tutorials/how-to-use-systemctl-to-manage-systemd-services-and-units

Not sure how to do "after mysql" but after network is good, restart is good etc.

mysql.service example:
/////////////////////////////////////////////////////////////////////////////////////////////////
# MySQL systemd service file

[Unit]
Description=MySQL Community Server
After=network.target

[Install]
WantedBy=multi-user.target

[Service]
User=mysql
Group=mysql
PermissionsStartOnly=true
ExecStartPre=/usr/share/mysql/mysql-systemd-start pre
ExecStart=/usr/sbin/mysqld
ExecStartPost=/usr/share/mysql/mysql-systemd-start post
TimeoutSec=600
Restart=on-failure
RuntimeDirectory=mysqld
RuntimeDirectoryMode=755
/////////////////////////////////////////////////////////////////////////////////////////////////
NGINX example:
# Stop dance for nginx
# =======================
#
# ExecStop sends SIGSTOP (graceful stop) to the nginx process.
# If, after 5s (--retry QUIT/5) nginx is still running, systemd takes control
# and sends SIGTERM (fast shutdown) to the main process.
# After another 5s (TimeoutStopSec=5), and if nginx is alive, systemd sends
# SIGKILL to all the remaining processes in the process group (KillMode=mixed).
#
# nginx signals reference doc:
# http://nginx.org/en/docs/control.html
#
[Unit]
Description=A high performance web server and a reverse proxy server
After=network.target

[Service]
Type=forking
PIDFile=/run/nginx.pid
ExecStartPre=/usr/sbin/nginx -t -q -g 'daemon on; master_process on;'
ExecStart=/usr/sbin/nginx -g 'daemon on; master_process on;'
ExecReload=/usr/sbin/nginx -g 'daemon on; master_process on;' -s reload
ExecStop=-/sbin/start-stop-daemon --quiet --stop --retry QUIT/5 --pidfile /run/nginx.pid
TimeoutStopSec=5
KillMode=mixed

[Install]
WantedBy=multi-user.target
///////////////////////////////////////////////////////////////////////////////////////////
NTP:
# /run/systemd/generator.late/ntp.service
# Automatically generated by systemd-sysv-generator

[Unit]
Documentation=man:systemd-sysv-generator(8)
SourcePath=/etc/init.d/ntp
Description=LSB: Start NTP daemon
Before=multi-user.target
Before=multi-user.target
Before=multi-user.target
Before=graphical.target
After=network-online.target
After=remote-fs.target
After=systemd-journald-dev-log.socket

[Service]
Type=forking
Restart=no
TimeoutSec=5min
IgnoreSIGPIPE=no
KillMode=process
GuessMainPID=no
RemainAfterExit=yes
ExecStart=/etc/init.d/ntp start
ExecStop=/etc/init.d/ntp stop

[Install]
WantedBy=multi-user.target
/////////////////////////////////////////////////////////////////////////////////////////
Cron:
[Unit]
Description=Regular background program processing daemon
Documentation=man:cron(8)

[Service]
EnvironmentFile=-/etc/default/cron
ExecStart=/usr/sbin/cron -f $EXTRA_OPTS
IgnoreSIGPIPE=false
KillMode=process

[Install]
WantedBy=multi-user.target

#############################################################
To mount a share:
[Unit]
  Description=cifs mount script
  Requires=network-online.target
  After=network-online.service
#		cifs	guest,uid=1000	0	0
[Mount]
  What=//192.168.1.240/share/shopshare/
  Where=/home/doug/shopshare
  Options=guest,uid=1000,workgroup=MOUNTAIN,rw
  Type=cifs

[Install]
  WantedBy=multi-user.target

This goes in /etc/systemd/system and has to be named home-doug-shopshare.mount
