Summarize this article in one sentence.
Every cookie dough recipe is a little different, so you should carefully review the specific recipe before proceeding. That said, most cookie dough recipes share the same basic ingredients in various proportions.  Use the following guidelines to prepare cookie dough if you have a list of ingredients but lost the instructions that go with it. Most cookie dough recipes use some type of fat, sugar, eggs, and flour. Salt and baking powder are not used as consistently but do appear in many cookie dough recipes as leavening agents. Butter is the most common fat used, but shortening is also used frequently. Butter creates crisper, thinner cookies, while shortening creates soft, cake-like cookies. Vanilla extract also appears in most cookie dough recipes. Note that ready-to-eat or safe-to-eat cookies doughs don't contain eggs. For best results, cut the cold butter into pieces and allow it to sit out at room temperature up to 30 minutes.  The butter should be soft enough for you to leave an indentation with your thumb. Do not let the butter melt, though. Softened butter and margarine are easier to combine with other ingredients. If running short on time, you can microwave the cold butter for 10-second intervals until softened. If using margarine instead of butter, make sure that the margarine contains 80 percent vegetable oil or more. If your recipe calls for both butter and shortening, you should cream them together with an electric mixer until smooth. Even if your recipe only contains one or the other, you should still consider beating the fat with an electric mixture until smooth. Doing so removes any lumps and allows the fat to mix into the dough more effectively. Use an electric mixer to beat in the sugar, salt, and baking powder or baking soda. These ingredients should be completely combined with the fat.  Cream these ingredients until the consistency and color both become lighter. This process creates air bubbles in the dough, thereby creating lighter cookies. Do not overbeat the dough, though, especially at this stage. Use an electric mixer to beat the eggs in one at a time on medium speed. Add the vanilla extract simultaneously or immediately after.  Beat until you remove all streaks of egg or extract. Consider leaving the eggs out at room temperature for 30 minutes before use. This makes it easier for the eggs to incorporate air in the batter, which creates lighter cookies. Use an electric mixer to beat in as much flour as possible, adding it slowly to the dough. When the mixer begins to strain, switch to a wooden spoon and stir the remaining flour into the dough that way.  Stand mixers can usually take the strain, so you may not need to do any stirring if using one. Hand-held mixers are less durable, though, and should be swapped out toward the end to prevent the mixer from burning out completely. Any chocolate chips, nuts, or similar ingredients should be stirred in after the flour. Saving instructions and baking instructions vary, so it is best to find instructions that are specific to your recipe.  Generally, you can wrap your dough tightly in plastic wrap and save it in the refrigerator for a week. Many cookie recipes bake around 350 degrees Fahrenheit (180 degrees Celsius) for 8 to 15 minutes.

Summary:
Review the ingredients. Soften the butter. Beat the butter and shortening together. Add the sugar, baking powder, and salt. Add the eggs and vanilla extract. Gradually add the flour. Save or bake as directed.