What to choose as decor items? White pumpkins are a good choice for the neutral porch. You can also add old wooden items, like this ladder for example. It will add a rustic note. Add some hay for additional decor.
When styling your porch, always keep the symmetry. That means that you have to put same items on the both sides of the door. This way of decor looks so pleasant to the eye. But, this does not have to mean that you have to place the same. You can place different items, but make sure that you keep the same height so they look harmonious.