It pays to tip the housekeeper every day.
Exchange a few pleasant words with the housekeeper if you see him/her--- and leave $2 or $3 tip each day. You'll get better service. Housekeepers are the most overworked, underpaid, underappreciated people in the hotel, so any gesture will be appreciated.
Knowing the housekeeperalso reduces the chances that your room will be burglarized. Dishonest housekeepers are less likely to target guests they have met. And if a thief enters your room while it is being cleaned and pretends to be you--- a common ruse--- the housekeeper will be able to spot the imposter.
Your bags aren't safe with the bell hop.
Even in elite hotels, luggage can be stolen right off the baggage carts in the lobby. Those these bags theoretically are in the possession of the bell hop, the hotel assumes no legal responsibility for the loss.
If your bag is going to sit for more than a few minutes, ask that it be placed in a secure room. Keep valuable items in the hotel safe.