I just looked at my "Ugly" book. He has a lot of stuff but the best tip was to mark a piece of scrap pipe of each size, bend it with your particular bender and see what the "take up" is.
In real life, if you make it "long" on both ends you can cut that one to fit and you then know where the rest should be bent.
I have done that before myself (starting "long") on a complex piece and cut it down to fit. When I was piping the lights into my screen cage I admit I was way over my head on this bending and I had lots of scrap but if you didn't know how many cork screws and crooked saddles I threw away you would think I knew what I was doing ;-)
