Does anyone know a good way to practice and train to become a better marching snare drummer?

Me and 2 of my friends plan on practicing over the summer alot, but we dont know where to start. We're preety good and can play basic exercises and cadences. Can anyone recommend any snare drum exercises/easy cadences/ warm ups that will help us improve, it will be much appreciated. We're all playing snare and we just need a good way to practice and get better.