Avoid Using Pesticides

So this may not exactly apply to you unless you're growing fruits and vegetables--unlikely if you live in the big city--but in case it does, or you know anybody you can teach not to use these, it's a huge step towards diminishing ozone depletion. 

Always opt for natural remedies because pesticides pose one of the biggest chemical threats against the ozone layer. For example you could weed your entire garden manually rather than spray the dangerous (though not to your immediate surroundings) stuff into the air that this planet shares.