You can contribute by supporting projects which reduce carbon emissions with reforestation or renewable energy.

Often times it's more sustainable to go into the store or restaurant or pick up the item or food yourself. You will avoid unnecessary packaging and potentially transportation emission from delivery. This depends obviously on distance and type of transportation you would use, since otherwise delivery can be actually more efficient, especially when the providers is running on electric mobility and multiple deliveries are carried.

Be cautious of labels like "environmentally friendly" or "100% natural" if there is no insights or information how it is archived. Also claims like "50% more recycled material" often don't reveal against what is compared. Spot them and dig deeper. In addition "CFC free" is not a achievement since it is banned since 20% years. Look for a seal or certification mark from a recognized, independent third party specializing in green claim. Also compare how sustainable the actual products is versus the packaging.

If use old appliances a lot they might consume way more energy then modern appliances. Look for ENERGY STAR qualified products and pick the model that uses the least amount of energy possible.

Good maintenance usually equals efficiency in regards of the things you own. Care for your appliances and they will reward you with lower energy costs and longer operating lives. Rather act earlier then later!