Here's an alternative to tung oil: a hand-rubbed linseed finish. It gives a deep, soft-looking gloss that gets better and better with age. It is very easy to do and almost impossible to screw up, although it does take some time. Yes, you can seal the grain with a paste wood filler beforehand if you want a glass-smooth finish, rather than the textured look of an open grain.
Here's how: take a tiny bit, really a few drops, of boiled linseed oil in the palm of your hand and start rubbing with the grain. It helps to cut the first coat with mineral spirits, by maybe a third, and after that full-strength. The heat generated by the rubbing with your hand is what makes it penetrate the wood. How many coats? The tradition is, "Daily for a week, weekly for a month, monthly for a year, and yearly for the rest of your life". The pic here has probably 7 or 8 coats - yeah, I'm lazy. One advantage of both linseed and tung oil is that, should you scratch the thing, another coat takes the scratches out.
WW

Edited by Bill Way - 9/17/10 at 11:20pm