Plastic
A lot of plastic pollution is caused by single used plastics such as plastic forks, knives, bags, straws, styrofoam, grocery bags, and other things. This is bad for the environment as well as the animals living in it. It also affects the humans, since humans sometimes eat the animals that have eaten plastic.
So, is the plastic fork that you used when having a party really worth it? Is the plastic knife you used during lunch at your work place really worth it? Maybe not.
So, instead of taking the plastic fork from a restaurant, grab some a real fork before you go. Instead of using a plastic straw, have a metal one with you, or don't use a straw at all. If the grocery store that you go to gives out plastic bags, be sure to take a reusable bag with you before you go. That way, instead of using a plastic bag, you'll have the reusable one with you. Also, paper bags can serve as a good alternative, since they're recyclable. There are many ways for not using single use plastics.