I read this tip in Eliot Coleman's
Winter Harvest Handbook last winter, and decided to try it out this year.
Instead of planting leeks a couple inches deep, and then hilling up around the plants as they get taller over the growing season, he basically pushes a 1-inch-diameter dowel about 9 inches into the ground, drops a plant (with its roots trimmed to 1") into the hole, and moves on. He wrote that this technique eliminated the time-consuming, messy hilling, and produced leeks that were beautifully and uniformly blanched for market.
The photo below shows the result of my test. I used an old broom handle as my dowel, marked at 9" from the end with a sharpie marker, to make my holes. Super easy!! My plants probably should have been a bit larger--I lost a few more than I normally would have when soil fell into the holes and covered the whole plant. Those plants that survived did not seem to mind being planted so deeply: