Qualifiers are always a requirement when we're talking about "a good spot for" threads. I don't consider it an exploit like some portion of the forum community does, when you find a "hot spot" that pays out well and you make use of it. You're just using what you're given. That said, I do find it incredibly, painfully, chew-through-my-wrists-to-make-it-stop boring to fly back and forth between two spots over and over.
My own, preferred passenger method is this:
My Orca has 1 Luxury Cabin, 1 First Class Cabin and 1 Business Class cabin. I take VIP's on Sightseeing tours, 3 at a time, and follow manual courses based on which location is closest to where I am. These are typically 2-3 stop trips per passenger, with an average pay of around 6 million and a total of 6-18 total stops, all usually within 500 Ly total range. They usually take about 30 minutes to complete, and when I'm done I usually have a number of interesting locations to revisit (Geysers and Fumerols - great places to gather resources).