Great customer service, let's see.
Pilots brief the Owners about the safety aspects of the aircraft, eg doors etc. introduce themselves and their colleagues, Inform them of the length of flight, any bumps or weather issues, check their onward transport details, tell them about the wifi.
If on an unattended fleet, show where the food and drinks are, and if time before departure, make a coffee/serve the champagne etc. If attended, introduce our ISR/CC.
If unattended, at FL100 or above, close the sonic curtain (if you have one), check the Owner is ok, Some Owners are very chatty, others, not so much... Cabin temp ok, wifi working, etc On Descent, inform how long to run, weather at destination and transport details.
Also before FL100, open the sonic curtain, tidy up the cabin in preparation for landing, stow loose items, confirm if the transport is in place etc.
Post flight, one will usually go with the Owners to their cars/FBO. Ensure all is well. Grab the paper work/fresh wx & Notams. The other will sweep the cabin for phones, wallets etc.
Then we tidy up the cabin, check the plan for the day hasn't changed. Arrange fuel, toilet service, restock and vacuum the carpets, clean every thing, check the ipads are charged etc.
Grab some food, plan for the next flight.