Research before you go. Bus travel is most pleasant when you are prepared. Check to be sure that buses cover your intended routes so that you can plan for alternate transportation when necessary. By doing so, you avoid the possibility of being stranded in an out-of-the-way Mexican bus station with no way to continue on.
Splurge on premium tickets. Don't worry, "premium" is not as bad as it sounds. Bus travel in Mexico is remarkably cheap, and the few dollars' difference between premium and local bus tickets might just be the difference between air conditioning and the aforementioned feathered seat-mate. Look for "first class" or "primera clase" tickets.
Double-check your destination. This is particularly important if you do not speak Spanish, as the ticket agents may rattle of a list of questions as you nod dumbly, thereby agreeing to ticket and/or bus changes you're unaware of. Find a friendly-looking bus station attendant or someone who looks as if he might speak English and ask for help. Other travelers are a wealth of ideas and assistance, and are generally willing to help. Before you get on the bus, ask your bus driver if the bus goes to your destination. In Spanish, ask "¿Este autobús va a [destination name]?"
Stay warm and well-fed. Mexican buses tend toward extreme air conditioning, so bring a sweater or blanket. This is particularly important on long trips, as eight hours under a cold air vent promises a miserable ride. Buses may stop along the way, but will likely only remain long enough to pick up and drop passengers off. Stock up on food and drinks before you get on the bus. If you're brave enough, buy some food from the local women who often board the bus at stops to sell local delicacies. Generally, such offerings are safe, but you face the risk of consuming food that has been sitting out in the sun as the women wait between stopping buses.
Visit the bathroom before you leave. Follow Mom's advice and go before the bus leaves; if your bus ride is long, you may not have another chance. The nicer buses in Mexico may have bathrooms, but chances are, you won't want to use them. The bus station bathrooms might not be the most pleasant of places, but you won't run the risk of being unseated with bus movement, and the smell should be marginally less invasive.
Prepare for Steven Seagal. Don't expect to see the latest Hollywood blockbuster on a bus in Mexico. Instead, prepare for old American movies and odd Mexican films. Steven Seagal is a popular choice. Brush up on your Spanish by reading the subtitles while listening to the English dialogue.
Make friends with the bus driver. When you board the bus, smile, say "hola" and verify the destination with the bus driver. If he speaks English and the bus makes several stops, ask him to make sure you get off at the correct destination. When the bus reaches your stop, he will likely call out to you in order to make sure you get off on time.
Look out of the window. Bus routes in Mexico pass through some fantastic territory, and also through areas that aren't safe to visit as a foreigner. Observe the pace of life as you pass through villages, cities, and acres of uninhabited land.
