Here is a quick and easy way to get the look of a jack-o-lantern without cutting into the pumpkin.
Using vinyl and my cricut, I cut out this image and put it on the pumpkin. In hind sight, I probably would have used one of the smaller pumpkins for this image. I might make some fun faces for the other pumpkins I have on my porch. When I was younger, we used to paint our pumpkins which was fun because we could paint them early in October and then carve them for Halloween. The vinyl works the same way except it is easier for me to do, and to be honest, I am not the best painter so this looks MUCH better (I am sure.)