You may feel small when it comes to this huge problem, but anything/everything helps
Recycle
Bottles being reused
This one seems super obvious and it really is. But a lot of people are not as adamant about what they put into the environment. There are about 5.25 trillion pieces of trash that float in the ocean at any given moment.
Think about how much of that trash could be recycled and reused. Not all plastics are available to be recycled but the amount that is just sitting in a landfill somewhere not being put to actual use is wreaking havoc on the welfare of the environment.
Donate or Up-cycle Old/Used clothes
Old Clothing on a rack
Any old piece of clothing that is unwanted to you, could be wanted by someone else. Donating clothes to any Goodwill, or clothes drop off bin, is as easy as putting the clothes in a bag and dropping them off.
You can also up-cycle any clothes you have. Taking an old sweatshirt that you don't wear and turning it into a crop-top or adding some stitching on it is so much better than going out and buying new clothes.
Commiting to Zero/Minimal Waste Living
Food Bought and Stored in reusable containers
This is as easy as buying cloth grocery sacks and bringing them shopping with you. Or ask for paper bags instead of plastic. There are some stores that let you package your own foods, like the ones shown above.
You can bring in Mason Jars and store the food so there is less waste being thrown out. Not a lot of people can commit to zero waste because it is a lot of time and effort, but it's the effort put in that counts.
Limit Water Use
A Water Faucet
Limiting water use is essential to keeping the environment alive and beautiful. You can take shorter showers, do not run water while you are brushing your teeth, and simply use the least amount of water needed.
Limit Electricity Use
A Power Outlet
Unplugging items when you are not using them will save you money but also can help the environment. Saving power and turning off lights, lamps, and fans when not needed is important.
While saving power, the companies that produce electricity are putting off less bad chemicals that can really affect the ozone layer.
Supporting Companies that Do Good Things for the Environment
Buildings
Always do your research and know what companies you are supporting. You could be funding a company that is overtly hurting the environment with no remorse.
There are a lot of companies that try to stay conscious about their affect on the environment, so always keep them in mind when buying/supporting a company.