I've started by cancelling my Amazon Prime subscription and no longer shopping with them.
X and Tesla avoid. Tesla's stock price has dropped massively in recent weeks, so this does have an impact.
Big social media and streaming companies such as Facebook and other Meta products, Apple, Netflix, Google, Disney, Snap etc.
Others such as Starbucks, PayPal, Nike, Coca Cola, McDonald's, Pizza Hut, Ford, Uber, Pizza Hut, Domino's etc.
And remember, it's not realistic for most of us to stop using all of these companies or sometimes even to boycott them fully, but a 10% reduction is better than nothing, 20% is an improvement on 10% and 50% is even more impactful again. If we all do as much as we can it still sends a message. Hitting these billionaires in their pockets speaks to them in the only language they know and says that their actions have consequences and they affect people.