i know Lusche aka Snailman had the starts down pat and could get max damage knowing where to hit with each bomb to use the splash damage to the best effect. maybe he will post his secrets.
There is no real 'secret'. Any veteran AH bomber pilot would know can maximise his 'landed damage' message and/or bomber score points. Just as you already said, if you are going for this kind of points, you want to kill a large number of reasonably large objects. Towns and some of the factories are best for that. To maximise your points, destroy as many of those buildings as you can. That's all there is to it.
But of course, every vet bomber pilot also knows that is very easy to pull off and often doesn't mean anything for the battle. Someone landing 'only' a few k of damage may have accomplished a much bigger feat. The landed damage messages and even the score sheet lack context. Just saying this because newer players often get kinda distracted by those numbers.
Almost forgot one thing: The 'landed damage' message and score damage points are only very remotely connected to each other. Two sorties with similar 'landed damage' messages can give very different amount of score points.
Looking for someone to help/explain some things things in running the bombers
Feel free to ask as many questions here as you like. I'm sure they can all be answered by us