When planning my trip to Barbados, flights from Dallas were expensive. Google flights really came through with the cheap flights. It looks for the cheapest one-way ticket going and coming. It is very likely you could be on different airlines coming and going, but you can save a lot. Instead of flying straight from Dallas, it was cheaper to get a flight from Miami. I saved about $200 getting two different flights than then flying straight.
If you are looking for convenience and don’t mind spending the extra money this is not your best option. For me, I wanted to save money and it worked out perfectly. Barbados was just one of many flights I had to get and I wanted to save where I could. When you get to google flights websites you type in your the dates and locations and google will give you the cheapest flights.
One advantage I had of using google flights is being able to have a few hours in Miami. So on my way to Barbados, I had a mini trip. We decided to go to Miami Beach during our layover. We had a few hours but by the time we took a few pictures and got something to eat, it was time to head to the airport.