Still on my tour of Empire RESs. Only doing Empire because I can check the BB whenever I have to replenish shield cells to see if there are any rank advancement missions.
Just stick around until one minor faction becomes hostile, then move on. Made about 50million in the last two weeks.
A few days ago, I made 2mil while cooking a pasta dinner. Each time I had more than 5mins until the food needed its next bit of attention, I had a punt around to see if there was anything worth shooting. Must have had a couple of dozen ships with more than 90K each. I ignore the little ships unless they are dangerous or higher.