Begin by painting a base coat using white paint (either acrylic paint or spray paint). The pumpkin doesn't need to be completely white; a base coat just means you can use less of the terra cotta paint for good coverage.
Once the base coat is dry, paint the pumpkin with two coats of terra cotta paint, allowing it to dry in between. Finish the second coat with up and down strokes to give it the texture and look of a clay pot. Allow to dry.
Use a small angled paint brush to paint the face black. Just follow the depressions on the bucket. If you get a little black paint out of the lines, simply let it dry and touch it up with the terra cotta paint.
Optional: Use home decor wax to give the pumpkin an aged and distressed look. Wipe the wax on each vertical depression of the pumpkin and then immediately wipe it back off, letting some wax settle in the depressions.
Hot glue faux leaves and berries around the front of the witch hat brim.
If desired, glue the pumpkin onto a candle holder. Then glue the witch hat to the top of the pumpkin.