>>15708176If you're just starting out, buy the first Writ of Challenge (50k IIRC) that makes more trainers come and just keep battling.
I recommend having a high level pokemon with a range of moves that can easily sweep everything (I use my Greninja@Amulet Coin with the moves Night Slash, Extrasensory, Water Pulse and Hidden Power Electric). Use Prize Money O-Power as often as possible too. I turn battles to set and moves off so it goes as quickly as possible too.
When you level up in the ranks, you get access to better Writs. My go to is Silver and Gold, which are 200k together, but you probably really only need Silver. I end up making over 1 million when I'm not side tracked, but I probably could make even more if I just focused on that without doing other shit in the process.
It gets to a point where all you do is roll Audinos and rake in the cash. Another bonus is I bring Greninja with other pokemon that I want to level to evolve for the pokedex in, although that sacrifices time. If new trainers aren't showing up (rare if you're not using Silver) I'd just go back to hatching eggs along that route and within 5 minutes more trainers would be back.
TL;DR: Buy writs, OHKO trainers, get money, repeat
