The ARIANNA experiment in Antarctica is targeted at detecting the radio emission of neutrino interactions in the ice. However, due to their antennas being deployed close to the surface, ARIANNA stations have routinely been used for cosmic ray detection. These fully self-triggered events have in-turn been used to improve reconstruction algorithms and to provide a proof-of-principle for neutrino detection and reconstruction. We will present the detected events and their characteristics. Also, we will elaborate on novel algorithms to reconstruct the cosmic-ray energy from a single station and to reconstruct the signal polarization from distributed antennas. While necessary for sparse neutrino arrays, these methods also provide new opportunities for stand-alone cosmic ray arrays to improve event statistics and reconstruction quality.