Your eggs need to be at room temperature, or they will not rise like you want. If your eggs are cold, immerse them in luke warm water for 2-3 minutes to bring them to room temperature.

This is another important ingredient, if your butter is warm or too cold, it will not be creamy when you mix it with sugars. So, your butter needs to be at room temperature so it can be whisked easily but not too warm that it turns into greasy mixture when mixed with sugar. It should be creamy. The butter at cold room temperature will also rise well. Keep your butter on the counter around 30-45 minutes in advance fit the best results.

In other case, just heat butter in microwave for 15 seconds. And rest it for few minutes before you begin. You can replace butter for margarine.

Try to use the best quality chocolate chips. You can also use your favourite chocolate and chop it but keep it in fridge, until you mix so it’s hard and doesn’t melt in batter.

DO NOT dig your cup in flour and fill it! You’ll pack your flour tightly and add extra flour in recipe. Always spoon the flour in the measuring cup for correct measurement. A single extra spoon can make your cookie comparatively tough.

Another tip is to always add 1/4 cup less flour than called in recipe. Feel the dough and see if more flour is needed. If you are still not sure bake one cookie with less flour and see how it turn out. If it’s too flat than add remaining flour.

If you are using a stand mixer, this tip is for you. Avoid over beating of eggs in cookie dough. You will fill too much air in cookies and when they will cool after baking, they’ll go flat. So annoying!

All cookie doughs do not require chilling so you can skip it sometimes. But when your recipe calls for it or your cookie dough is soft and greasy, chilling is a must. Or you will end in flat crispy cookies. They won’t be as soft as you would want. Another reason to suggest chilling is the cold centre of chilled cookies cooks slowly compared to outside. Giving you chewy outside and super soft inside. This step is also important because it gives flour and other ingredients time to merge together, and hence provide heightened subtle flavor. Chill dough overnight for best result. If you are in hurry, scoop cookie dough baking sheet and keep in fridge for 30 minutes. They’ll chill quickly.
Lastly, if you chilled dough overnight and it is very cold, allow it to rest on counter for about 10 minutes so it is not to cold when it reaches the oven. If you don’t the bottom of will be golden and center will be still undercooked.

8-10 minutes works best most of the time for me, but ovens behave differently. So, set your timer to 6 minutes and then look for visual sign of completion of baking.

Visual signs win always. You need light brown edges and center will be under cooked for soft cookies. When you lift the cookies from baking sheet and transfer to wire rack, they’ll be very soft, but they’ll firm up as they cool. For chewy cookies, your edges will be brown, and center will be set.

You can bake without baking paper but it really helps and doesn’t allow cookie to spread too much. Flat cookie is crispy and chewy instead of being soft and gooey.

Another reason is the extra layer between the metal tray and cookie allow them to get golden instead of getting too dark brown or burn.

You can add your favorite nuts in cookies without altering anything in recipe. For around 3 cup flour batch of cookies, you may add up to ¾ cup nuts of your choice.

If you want to turn a plain flour cookie into cocoa cookie just reduce flour and add an equal amount of cocoa.

For an instance, if you wish to change 3 cup flour cookies recipe to chocolate cookies you will add ¾ cup cocoa powder and use 2 ¼ cup flour. You might need to make more adjustments but this is a good place to start and develop a new recipe.

Usually, 325-400 F (163-204 C) is recommended but can vary depending on the cookie, your elevation (sea level vs high up a mountain), and your oven's heating element and internal thermometer.

Now, you can’t trust oven temperatures. It’s generally slightly off from what you set. So, for best results use a thermometer. If you really care about cookies and baking invest in an oven thermometer. It’s worth every penny and very cheap for the job it does.