1) Win the slot machine (random): This is the case in Loot 2.0, where cost is what matters and not dpp. High efficiency rated gear could make this more likely but no one really knows the function of efficiency to return unless there's hidden data somewhere
.
2) Sell Markup Loot + Skills (random + some control by player): If the slot machine is kind to you, you can cover your losses selling MU loot. If not, you can't. You could potentially sell your skills but then you might have trouble with weapon/tool/crafting progression. But maybe that doesn't matter to you...
3) Resell (Requires initial ped investment). Buy low sell high.
4) Sweat/Pick oil. Fap service, etc: Sweat/Pick oil is free. but other services require initial investment in a tool like Mod 2350 if you want people to pay you for the service, and usually mostly hired during event times like migration.
That's it I think. This game is pretty transactional. You pay MA a cut for a chance to loot items, you sell items for MU, rinse and repeat. This doesn't cover things like support dps and free fap service for skill but you don't really get paid for those and you have to trust he person you are supporting to pay you....