OP did not say which hotel, but here is some specific advice:
At GCH, avoid bringing bags to Bell Services in the lobby. Although usually there is not an issue, there is sometimes a line stretching across the lobby. Guests arriving on a bus might be forced to use bell services in the lobby, but anyone arriving by car (or taxi) can have bags checked directly from the car. Guests checking out can have bell services pickup bags from the room.
As for tipping, I tip twice.