Hotel room security tips

I love hotels. Well, specifically, I love good hotels, but I worry about my safety. Once in a bad hotel I became truly glad I had used the security chain on the door, because some other people turned out to have a key which opened my door, so they tried to come in. People tend to think a good hotel is a guarantee of their safety, but this is not the case. Bad things can happen anywhere, so it is good to be well-armed with a few hotel security precautions and tips.
When you check in at the front desk, never allow your name to be spoken. Hand over a credit card and a business card instead. And when the clerk gives you the key, never allow the room number to be said. If the clerk says the room number instead of writing it down, insist on a different room.
Upon entering the room check to make sure the door has a deadbolt lock and a security chain. Some people even take rubber door stoppers in their baggage. Next check the windows: do they lock? Can they be opened in an emergency?
Never leave your hotel room door open; not even to go down the hall to get ice. This just allows people to slip in unnoticed. Several assaults have happened this way, even in four star properties.
When you leave the roon, place the 'Do Not Disturb' sign on the door. This makes it look like the room is occupied. Leaving the radio or telly turned on gives the same impression.
If you are concerned about staff at the door, call the front desk to confirm their identity before opening your door. Also, you can get room service to call before delivering food.
And when you leave the room, ensure the windows and balconey doors are locked, and that the main door closes and locks behind you. Security starts with you!