By not playing into the system. I don't pay for subscriptions of any kind. I don't buy a fancy coffee every day. I cook most of my meals. I plan to start a garden to grow my own food. I'm learning to sew my own clothes. I buy things (usually) only when I genuinely need them. I don't throw things out became they're broken, I fix them. I don't throw things out because they're "not trendy" anymore. I will pay more to buy from a smaller competitor then the cheaper monopoly. I will go the extra three miles and pay for not free shipping to avoid giving money to companies whose ethics are deplorable. I have credit cards with rewards and I pay the bills every month so that I make money off of them. If I live long enough to get my next degree, I'm leaving the company that has used me for years without proper compensation (they're paying for the degree).
I make sure that a company has earned the right to have my hard earned money before I consider giving it to them. It's hard but at the end of the day when I see a social media post about some CEO taking their 10th tropical vacation this year I'm happy to know I didn't fund it.
Additionally: I also buy A LOT of things second hand.