More often than not, we can’t always fly from point A to point B. Instead, we need to make a connecting flight through a third airport, and as many of you have already experienced, that’s when the problems start.

It all comes down to the connecting time the airline considers legal between flights.

In some cases, a legal connection can be as short as 40 minutes.

It may be legal, but in my book, it’s a ridiculous proposition, considering all the things that could go wrong—a possible delay on your original flight, the distance it takes to walk between gates, and whether or not your baggage will make the second flight.

My rule: never let the airline book you a domestic connection of less than 90 minutes. If they do, you stand an excellent chance of missing your flight, your bags being lost—or both.

Overseas it’s even worse. A legal connecting time at London’s Heathrow Airport is two hours.

But here’s what they won’t tell you: The airport considers three hours a legal connection time for your checked bags.

Do the math. Give yourself a three-hour connection, no matter what the airline says.

But when you do have a long layover, there are ways you can take advantage of that extra time:

• How to Make Your Vacation Longer With Stopover Flights
• Some of the Best Airports for Long Layovers
• Airports That Help You Get Some Shuteye in Between Flights

Keep reading for more travel tips.