Avoid big box store
In wealthy countries today, consumers travel by car to do their shopping in big box stores built on the edges of urban areas. They store their food in freezers, which use more energy because products are sold in overpackaged portions. This system gives large retail organizations a high degree of control, which they use to force down farm prices or to import products from countries where labor is cheap and environmental legislation almost nonexistent.
Shop closer to home. Every new supermarket that opens causes hundreds of jobs to be lost. Pollution and congestion would be a fraction of what they are now if consumers frequented their local shops.