Hold the corps to account, vote with your wallet, demand that they reinvest profits in education and betterment and development of these geographic areas.
Clothes is a nice and easy one to begin with choosing an alternative for because it's a much more simplistic product with a more easily traced supply chain. Phones, computers and cars are something we'll likely struggle with for a long time.
For anything else, the public will likely need to demand change as I doubt a superior or equal alternative will emerge. With that said, products like the FairPhone are very interesting, though I haven't used one.
Food is something that'll largely hinge on your geographic area and availability of produce that makes sense.