Here are my additional inputs when you are in mexico:

If you will go to the bus station, you need to carry your own bags to the official taxi booth at the bus station. You may find people who may want to assist you nearby. You do not have to allow this person to help you carry your bag. If you want to accept the assistance, you can tip the person $1.

If you take a cab from the street, public taxi are metered. However, if you will hire a taxi in the airport or hotel, these are rated depending on the price you agreed. They do not use a metering device.

You will also find it interesting that in Mexico, there are informal entertainers in a stop light. Yep, you might see people eating fire, juggling, etc. once you stop in a stop light, tipping with these people is your discretion.

Check out for more tips!