A fireplace mantel can be a visual centerpiece of your room, and you can keep your oak fireplace mantel in great condition with minimal effort.
When you have a beautiful oak mantle, the mantle itself is a centerpiece and does not necessarily need to be cluttered with a lot of knick knacks. Take a look at your mantle, and determine whether or not it's become a catch-all. Remove unnecessary items from the mantle; this will make it easier for you to keep clean.
At least once a week, use a soft cloth to wipe down the mantle. You can use a commercial furniture polish, but be sure to spray just a little on the cloth and not directly on the mantle. If your mantle has scrolling or other detail that is hard to clean, try using a cotton swab or a soft paintbrush.
Because your mantle will be layered in soot and debris from your fireplace, you will need to occasionally clean the mantle thoroughly. Use an oil based wood cleaner to wash the wood, and reapply a protective oil layer at the same time.
With a little effort, you can keep your oak mantle looking new.