This is for future me as well ;) Source listed below.
Disable wireless drivers:
Disable loading the drivers for bluetooth and WiFi. As well as reducing the number of interfaces it may reduce power usage.
# cat > /etc/modprobe.d/raspi-blacklist.conf <<EOF
The bluetooth service is not required
# systemctl disable bluetooth
# systemctl stop bluetooth
The Pi is going to use simple uni-cast DNS - multi-cast DNS support is not required.
# systemctl disable avahi-daemon
# systemctl stop avahi-daemon
The Pi isn't being used with button. Disable the TriggerHappy daemon (not[e] that it is a init.d service)
# systemctl disable triggerhappy
# systemctl stop triggerhappy