I wipe on Mineral Oil until the board is saturated ... generally, 5 coats over 24 hours. Then, I wipe on/wipe off my board butter, which is made 2/3 Mineral Oil, 1/3 Beeswax.
The consistency of the board butter is like applesauce in your hand as it melts ... you don't need to heat the board butter to apply it, as some "stiffer" recipes will require. Once the butter is wiped off, the board feels buttery soft.
That's the finish I use on everything I'm selling these days, though I keep thinking I should use "Good Stuff" for my non-food ready items. Haven't gotten there yet!