To julienne means to cut into narrow, fine sticks that can measure from 2 to 3 inches long and 1/8 inch square. A finer julienne measures 1/16 of an inch square.
First, determine the length of your julienne and, using your chef's knife, cut the vegetable into pieces. Next, trim the vegetable so its sides are straight and at right angles.
Then, holding your knife vertically, slice each piece into 1/8-inch panels.
Finally, neatly stack the panels, or lay the panels out on the board, and cut them lengthwise to create uniform matchsticks. Remember to keep your fingers tucked in, and out of the knife's path.
For a finer julienne, simply slice thinner panels and thinner matchsticks. A larger matchstick--roughly 1/4 inch across and 2 1/2 inches long--is called a baton.