Use the Right Fat
Nothing is better than the flavor and richness that butter adds to cookies, but maragine will also produce good results as long as you use a margarine that contains at least 80 percent vegetable oil. If it's not clear on the front of the box, check the nutrition label: The margarine should have 100 calories per tablespoon. Margarines with less than 80 percent vegetable oil have a high water content and can result in tough cookies that spread excessively, stick to the pan, or don't brown well.
Metal or plastic measuring cups are intended for dry ingredients, such as flour and sugar. When you measure flour, stir it in the canister to lighten it (you don't need to sift). Gently spoon flour into a dry measuring cup and level the top with the straight edge of a metal spatula or knife. Don't pack the flour into the cup or tap it with the spatula or on the counter to level.
Measuring spoons are used for smaller amounts of both dry and liquid ingredients. Most sets of measuring spoons have a tablespoon, teaspoon, 1/2 teaspoon, and 1/4 teaspoon.
Glass or plastic cups with a spout are meant only for liquids. A 1-cup, 2-cup, and 4-cup measure are essential for measuring liquid. If you use a liquid-measuring cup for flour, you're likely to get an extra tablespoon or more of flour per cup, which is enough to make cookies dry.
Chill Dough Properly
The chilling time given in a recipe is the optimum time for easy rolling and shaping. If you need to speed up the chilling, wrap the dough and place it in the freezer. About 20 minutes of chilling in the freezer is equal to 1 hour in the refrigerator. Always chill rolled or sliced cookies made with margarine in the freezer.
To always have cookies at the ready, you can freeze dough in a log so you can just cut off a few slices and return the log to the freezer. You can also scoop the dough into balls with a small ice cream scoop and freeze on a cookie sheet. Once frozen, transfer the slices or balls to a resealable freezer bag and pop back in the freezer. Thaw them 10-15 minutes on a baking sheet before putting them in the oven.
Choose the Right Cookie Sheets
Cookies bake more evenly on light to medium-color sheets, whether shiny or nonstick; dark cookie sheets may cause cookie bottoms to overbrown. Insulated cookie sheets cause slow baking and tend to yield pale cookies with soft centers. Use jelly-roll pans only for bar cookies -- other types of cookies won't bake evenly in a pan with sides.