I tip my parking van driver if they pick me up at my car as I'm getting out and run out to grab my bags. A tip is to recognize going above and beyond to make my life better. I do not tip the maids for a clean room. Cleaning it is their job. It is not the van driver's job to carry my luggage or follow my car to where I park. It also isn't the hotel van driver's job to bring our keys to the airport so we can skip checking in all together. Waiting for us, loading my bags and bringing me the keys are above and beyond and are rewarded with a monetary incentive.