A penetrating oil finish. Chinese Wood Oil is usually applied with a rag but can be brushed. Cover the wood with a generous amount of the oil and let it soak in for at least 20 minutes.
Re-apply oil to any areas that have soaked in all the oil.
If you desire a very smooth finish and want to fill the grain of open grained wood flood the surface with oil and use 600 grade wet and dry paper to wet sand the surface. The sanding dust combined with the oil will produce a filler that will help fill the pores. Steel wool (grade 00 and finer) is sometimes recommended for this purpose.
Before the oil begins to cure and becomes tacky wipe all the excess from the wood with a clean lint free cloth. This method works well with woods like Walnut or Cherry that have relatively small pores. Wood like Oak or Mahogany that have larger pores may need an additional fill, fine pumice is very satisfactory. Apply a coat of oil to the wood then sprinkle a little (a pinch between finger and thumb is sufficient for approximately 125 square cm.) pumice onto it, sand the wet surface with 600 grade wet and dry paper. The sanding will make a paste of wood dust mixed with pumice that will blend with the colour of the wood and fill the pores. Continue sanding until the pores are full, adding pumice as necessary.
When you have finished sanding wipe off any remaining filler with a rag -be sure each time you apply oil to finish off with a clean dry rag to remove all excess oil, which if allowed to cure above the surface will give an uneven texture to your finish. Should this occur it is not hard to repair.
Use a good hand full of "00" or finer steel wool, or alternatively for a flat surface 800 or finer grit wet & dry and a cork block to assist in keeping things square with thinned oil to act as both a lubricant and your next coat - cut back the entire surface evenly in the direction of the grain until satisfied.
After about every 5 to 10 applications of oil this process is recommended in any case to ensure a flat surface throughout the job. Apply as many additional coats of the oil as you wish to achieve the desired finish. Allowing at least 6 hours between coats, wipe on a sparing coat with a rag, leave for a half hour or so and wipe off excess well - remember that all excess oil is removed, and so there is no reason after your first coat or two to apply heavily, as you would discard useful product with no benefit to the work.