Different types of energy conservation?

for my final project in my science cl, i decided to do different types of things that conserve energy for houses or a whole house that is all about conserving energy and has no harmful effect on the environment. so far i have earthships and chicago greenroofs and solar paint. Have anymore ideas for what i can use? the earthships take up most of my report so far so i need more stuff and it is kinda hard to look for things such as that on the internet when you have know idea what you are looking for