DIY It Yourself Materials
This one is pretty self spoken and a easy game to create so let just start with making the materials. I would start by find tall glass bottles if a interesting soda, beer or etc that everyone can empty the day of or in advance to bring. You will also need a flat surface with some semi sticky material for everyone to use.
Now we need to get the rings and the easiest way to do this is by buying them. I would just go to amazon again to purchase a cheap set of rings to use. You could get creative and make the rings as well out of something like clothing hangers or something that is circular.
How to Play the Game
To play the game everyone gets a number of rings to toss. Whoever gets the most to hit wins. If by chance there is a draw, the people left need to toss the rings again to see who can get the most to hit. So simple and rewarding to play this game.