I have a 12 year old fence that had been stained after it was put up. It was looking pretty worn from the weather so I power washed it and brought some new life into it. I like the new look but am unsure if I should again re-stain it? We like the natural look of wood and would not paint it, but if it would give us more years I would again put some type of stain or preservative on it. What are the best products out there, if I need to put anything on at all?