I learned this one the hard way. On a stop in Belize, I assumed the excursion operator would take a card. They didn't. I spent the first twenty minutes of what should have been a great morning scrambling for cash instead of getting on the boat. Excursions and ground transportation are the two pieces of a trip that most often go sideways, and they're the two pieces travelers are most likely to book on their own at the last minute. So let's sort them out before you go.

The one rule about shore excursions - if you take nothing else from this page, take this:

On a cruise-line sponsored excursion, the cruise line is responsible for getting you back to the ship when a tour delay affects your return. On an independent excursion, that responsibility is generally yours.

That's the whole trade. Cruise line excursions typically cost more, run bigger groups, and follow a fixed script. Independent tours can be cheaper, smaller, and a better fit. But if traffic backs up or the boat runs late, the cruise line's tour is responsible for getting you back on your cruise.  A hold-up on a privately booked excursion gets you a phone number for the port agent and a very expensive flight to the next stop.

Here's how I decide:

Book through the cruise line when the port day is tight, the excursion travels far inland, you're in a destination where you don't speak the language, or it's the kind of trip where missing the ship would wreck the rest of the itinerary. Alaska glacier flights, Roman ruins two hours from the port, anything involving a ferry - cruise line.

Book independently when you've got a generous buffer, the activity is close to the pier, or you're on a land-based trip where there's no ship to miss at all. City walking tours, beach clubs, food tours, museum tickets, snorkeling within sight of the port - independent is almost always better value and a better experience.

When you're not sure, ask me. I'd rather spend five minutes on a text than have you email me from a pier in Cozumel.

Ground transportation - Getting from the airport to your hotel, or from the airport to the cruise terminal, is worth arranging in advance more often than people think. For most bookings I arrange transfers directly, and if I've put your trip together, that should already be handled - you don't need to do anything here. Where it comes up is the in-between stuff: a city I haven't booked you into, a pre-cruise night you added yourself, a return leg that shifted, or a destination where a prearranged private car simply costs less than what you'd pay standing at the curb or using a ride share service.

A few things I'd tell you regardless of who books it:

• Private car vs. shared shuttle — shared shuttles are cheaper and stop four times before yours. With more than two people and any luggage, private is usually worth the difference.
• Cruise port transfers — build in more time than feels necessary. Port traffic on embarkation morning is its own weather system.
• Europe — for most city pairs, the train beats a car and often beats a flight once you count the trip to the airport. Ask before you book a short-haul flight.  Europe Travel Planning

Cruising from Galveston? See my DFW-to-Galveston parking and terminal guide.