My wife and I visited Mexico City. Here are 7 things we did right — and 2 mistakes we'd avoid making next time.

My wife and I visited Mexico City in January. Thomas E. Franklin My wife and I traveled to Mexico City and loved the city's lively and welcoming energy. I'm glad we used public transportation and took time to explore the diverse neighborhoods. Next time, though, I'd pack warmer clothes and spend less time traveling between neighborhoods. My wife and I are active 60-year-olds who love exploring new places, eating well, and learning about other cultures. As a photojournalist, I've spent time...