• Use the correct pan. Grace Young recommends a 14-inch flat-bottomed carbon-steel wok. Second choice is a 12-inch stainless-steel skillet (which will be a little small if greens, such as spinach, are used). Avoid nonstick pans -- including woks -- which should not be brought to as high a temperature as needed for stir-frying.

• Invest in a good knife for prepping the ingredients -- a chef's knife or cleaver. And then maintain it (within five uses, it will be dull, Young says). If you don't know how to sharpen a knife with a stone or steel, try a knife sharpener (she recommends Chef'sChoice, for under $40).

• Have all your ingredients prepped before starting to stir-fry, lining them up in order of use, if possible. The cooking process itself goes quickly.

• Cut the ingredients to uniform size -- or some will be overcooked.

• Cut beef against the grain or it will be tough; it's often better to do so with chicken, too.

• Add dry ingredients to the wok, not wet. Pat protein and vegetables with a paper towel, or use a salad spinner for greens.

• Preheat wok before you add ingredients. When it's hot enough, you should be able to sprinkle some droplets of water on the wok, which will instantly evaporate.

• Use oil with a high smoking point (so you can heat it to a high level) -- never olive or sesame oil. Peanut, canola or other vegetable oils work well.

• Don't overcrowd the wok with ingredients. Never use more than 1 pound of protein (and for beef and scallops, the limit is 12 ounces). For vegetables, limit the amount to 4 cups at a time. If too many ingredients are cooked simultaneously, the wok loses heat and you'll be braising instead of stir-frying.

• Stir-fry vegetables in order of their density, beginning with hard vegetables (carrots and broccoli), then adding medium-hard (bell peppers and snow peas) and then soft and leafy vegetables (spinach and bean sprouts).LEE SVITAK DEAN