larrysb said:
For the life of me, I wish I could figure out how.
Larry,
It is kind of a long story; but basically...
You can't start out buying an expensive airplane and try to make it pay for itself. (I mean you can, and people do, but it is a very tough row to hoe.) Trying to go 135 or some other commercial operation is near impossible, and my hat is off to anyone who makes it work.
For those without a bazillion hours and bazillion dollars, the only other way is to use the airplane in some sort of business -- not where the airplane itself is the business; but where the airplane accelerates the business.
Let's take a very real world example (using fictional people, places, and business ventures.)
Let us say there is a business person who does nothing but close sales for his company. He has a team of people who go around and get people interested, and maybe even do an initial meeting. Then our example businessman slides in and closes the sale. As this happens more and more, soon the businessman can hire several people to generate leads. Before he knows it, he doesn't have time to close all the sales. He tries to get his sales team to close the sales, but they just don't have the 'magic' that this man has from his years of experience. So he starts to lose money.
Let's say that he loses a sale a month, and the average profit on a sale is $20,000. Hmmmm...if he could find an airplane that only costs $10,000 per month, he is $10,000 a month ahead...because being able to go on HIS schedule...to an airport close to the meeting...and maybe even another meeting in another city the same day...and this is something the airlines just can't deliver.
This is exactly how it is done.
As another example:
Let's say we have a real estate investor. No matter how much a property appreciates, obviously, the less you pay for it, the more you make when you sell it. (And if you are holding it and renting out units, the less you pay for it, the more positive your cash flow, the higher your IRR, etc.).
Let's say that our investor likes to invest in waterfront property -- one of the current booms, and he wants to limit himself to the area from Virginia Beach to Houston -- with a strong focus on the Hilton Head to Destin subset of that coast line.
The way that he finds property as low as possible (which is pretty hard to do by any means) is to look at a lot of properties. Basically, he has to see a lot of properties and make a lot of offers (which are rejected...until the right mix of things happen that allow him to buy it more cheaply.) He has a day job -- (the guy above who closes sales). He really doesn't have time to be flying all over the south east looking at property.
BUT WAIT!!! He owns an airplane. He can combine some of these trips and simply hop from a sales meeting to a property...and home to sleep next to his wife that night!!
Playing the real estate game at this level, he may be buying properties that are anywhere from $300,000 per UNIT and up. A small, 10 unit condo would be $3,000,000.
If having the airplane allowed him to look on the Internet, find properties that appear to be selling for less than they are worth, go look at them to make sure there isn't a 3-mile-island right next door, and find one cheaper...one deal could result in enough savings to buy and fly the airplane for a year!
Of course, deals don't come easily. It might take 3 years to find one where you could save or make $300,000. But they are out there...and the same goes for the sales thing above. Maybe no more sales are made for the first 8 months, but then a $160,000 home run pays for it all.
Notice that both examples work because they stretch the time of the person who makes the money.
At some point, you reach a point, where the only thing limiting you is your time. And an airplane is a time machine. It gives you more -- which results in more money. It's not simple, and you better be able to ride out the months where there is more going out than in...but if you're careful, eventually, having more time will result in more money at the end of the year WITH the airplane, than you would have had WITHOUT the airplane.
To dreams that come true...and the best type of dreams that come true...those that help you to realize even more! Good and safe flying, Dave, have fun and make it pay for itself. There ain't nothing better. 
And may your Z expand by the fouth power as your costs cube.