I found that using the city bus from the airport saves money and helps the planet.
I found private rooms in guesthouses were often cheaper and more comfortable than crowded hostels.
I was in a taxi in Mexico City and the driver was REALLY friendly. I told him ALL about my hotel and when I was leaving town. Later that day, someone tried to break into my room. I think the driver told someone. Now I only give VAGUE answers to questions. It saves MONEY and stress. Please be CAREFUL who you talk to.
Back when I first traveled Europe, I bought point-to-point tickets everywhere. Then I learned about regional passes and flexible dates, which cut my rail costs in half.