After harvesting my pumpkins, would it be a good idea to plant
something in the late fall, or early next spring to help give the soil
something back (without taking away what the pumpkins usually use up)
before I plant pumpkins next year? If so, what would be good to
plant?

Other than rotating patches which I have been doing, is there anything
else I can add to the soil which appears to be getting tired?

Thanks,
Matt