As above; i only really “service” stuff when it starts to complain.
Degreaser – fairy liquid in hot water.
Lubricant – light machine oil.
Headset – Strip, clean, oil, reassemble.
Bottom Bracket – Strip, clean, oil, reassemble.
Freewheel – Strip, clean, oil, reassemble.
Hubs – Strip, clean, oil, reassemble.
See the pattern? 😉