An auto loading shotgun normally has less recoil then the other types. A heavier shotgun has less recoil as well. Other then that ammo selection is huge. If you're shooting clays with light loads some autos won't eject the empty case.
Some of the specifications that a person should look for in a shotgun to reduce recoil include weight, manufacturer's catalog, muzzle velocity, ejecta and the powder type used in the shotgun. These are also considered as some of the things that control the shotgun recoil.