Auto mount Samba (SMB) using systemd

/etc/systemd/system/mnt-shares.automount

[Unit]
Description=Automount shares

[Automount]
Where=/mnt/shares

[Install]
WantedBy=multi-user.target

/etc/systemd/system/mnt-shares.mount

[Unit]
Description=Mount shares

[Mount]
What=//192.168.3.10/shares
Where=/mnt/shares
Options=username=smb,password=123456
Type=cifs
TimeoutSec=30