I go to a brick and mortar store (support local economy)
Good luck finding a brick and mortar store that carries the particular discontinued good you want. Do you plan to support global warming by repeatedly driving to all local pawn shops and thrift stores for years until the item you want finally happens to show up?
I don't use self checkout registers (support local employment)
Supporting inefficiency is the broken window fallacy.
There should not be multi-national corps, period. International trade still be achieved by company A in country A importing to or exporting from company B in country B.
Say I, the owner of a hypothetical small business, want to sell my company's products to people who live in 20 different countries. How should I go about efficiently starting 20 different companies to do so?