An interesting effect I've seen is that you can commandeer civilian ships using tug boats.
IE. you plug a tug boat on your home world, when civvies build a ship, you tractor it, and somehow it's your ship now.
I've used seized civilian ships as part of a cargo group and what they transport gives them (and you) wealth.
I was thinking that you could put colony and cargo ships with jump drives (for sorium cost), let civvies build them, then seize and scrap them.
If you commandeer enough and have good fuel efficiency, you could set up a perpetual back and forth between Earth-Moon (transport colonist to moon, transport them back) that generates wealth out of thin air so the civilians keep building ships for your scrapyard.
....
Might be able to play a zero mining game that way. >.> Just need to account for every single resource and SM yourself something ridiculous like 20 shipping lines.