There are lots of projects out there that will help you attract more birds & butterflies to your garden. Basically, anything that provides the appropriate food, water, and shelter is going to do the trick!
But you can go a step farther with these kinds of projects by using recycled materials. I've included three ideas that will get you started, and I am telling you there are gazillions more videos and tutorials where these came from. If you have a particular animal for whom you want to provide food or water or shelter, do a little research to figure out their preferences, then see if someone has made it before!