First, remove all vegetable matter that could allow pests to overwinter, along with any weeds that may have taken hold. Then, when the plot is “clean,” spread a thick layer of mulch, such as pine straw, whole or mulched leaves, soil amendment or composted wood chips – an inch or more – over the entire surface. That’s it. Now you can go carve a pumpkin.
Don’t till now or at the beginning of next season. Tilling destroys the structure of the soil that has been such a boon to the plants in your plot. The churning action of tilling (not to mention the results of walking behind the tiller) eliminates air passageways, compacts the soil and disrupts or kills the earthworms and other beneficial critters that make your plot a wonderful source for plant nutrition.
Sometimes, less is better in your garden.