The single most powerful move one can do to deal with external business is to replace them with local businesses. An effective way to create and maintain local business so that they don't die or metastasize is to create cooperatives.
Large corporations will continue to stack the deck against local production and self sufficiency by externalizing their costs and obtaining subsidies (cheating) while making it appear that we are getting cheaper goods from them than we can create. They are cooking the books. Remove their influence by avoiding them whenever possible. When we buy cheap goods built upon ecological damage and functional slavery in other countries (or in our own) we are not really getting a good deal. Permitted criminal behavior is not a "good deal". Benefiting from corruption is not a "good deal".
Boycott. Replace them. Always insist on paying the full price; otherwise someone less fortunate than us is paying for what we are getting. That is not fair. The planet is rebelling. Listen.