Couple of things to say here.

1. I hate having a surcharge added automatically (as is often automatic for groups of >6 or so) and then expecting a tip on top of that.

2. I generally tip heavily. As in 20-25%. The few extra dollars means nothing to me, but is often significant to the recipient.

3. I'll use a bellman if I have more than one bag, but will refuse if he/she just grabs it without asking.

4. I'm of mixed feelings about tipping in hotel rooms. I usually stay a week and check out on Saturday AM. Will that week-size tip go to the entire housekeeping staff, or just the Saturday on-duty person? If I knew it was shared, I'd be more generous.

5. When service is bad I tell the server and the manager. Leaving no tip makes me look like a stiff and sends no message. Speaking up does. I will leave 5-8% in that case, though, since I'm aware of the tax laws and see no reason that even incompetent staff pay to serve me.

6. If food is bad, I tell management, but don't reduce the tip. The server didn't cook it.

7. If I take a table but only order an appetizer (common when arriving late or jet lagged) I tip very large since the waiter only has a few tables on which to earn a living.