Finishing a porch is the process of decorating the interior and exterior shell for the purposes of appearance.  The most basic element is how to cover the ceiling and house wall.  Installing tongue and groove cedar bead board is a popular look but can be expensive especially on a large porch.  Railings are usually required on porches just like decks and can be installed to the inside or outside of a screen wall. Some porch builders build knee walls in the place of rails and use siding materials and trim to match the house.  A variety of attractive screen doors are available.  Soffits and fascia are usually selected to match the house as well.  Operable windows are a nice touch and can make the porch more versatile for colder weather but can be very expensive.  Trim of all kinds can be installed to the inside and outside of the porch.  Individual’s tastes do vary as to what looks nice and what looks over-decorated.  A number of excellent products are available for these purposes.