Have baking pads or mitts ready for handling hot pans.
Have cooling racks ready and a convenient place to put them.
Acquire a timer that signals with a ring and use it to time all your baking.
Turn on your oven about 20 minutes before using. The temperature will be more accurate when you start baking.
Set your oven to 350 degrees. When the heat shuts off, check the oven's temperature with an oven thermometer.
Place the thermometer at different points (front and back) and at different levels (bottom, middle, top shelf). The results will let you see how to best bake cookies in your unique oven.
Use cookie sheets with low sides. Heat will circulate around them evenly and give you a better bake. Also make sure that there is at least 1 to 2 inches of space around the pan. This will let the oven heat evenly. Make sure that all the cookies on each baking sheet is about the same size.
When your recipe reads -- bake for 10 minutes; set your timer for 8 minutes and check your cookies. Each oven is different. A good baking practice is to check on baking progress. Use a spatula to gently lift a cookie to check the bottom. Cookies continue to bake on the hot sheet after they are removed from the oven. Take cookies out a little early rather than when they are completely done. Establish a minimum and maximum baking time for each type of cookie.
Cookies baking too fast on the bottom is usually caused by excessive bottom heat in the oven. Try putting one shelf at the lowest position and cover the shelf with a piece of aluminum foil or an empty baking sheet. Put the cookie sheet on a shelf half way up in the oven. This will cause the heat to flow more evenly around the cookies and not overbake their bottoms. Use double pans to bake on.
New pans or those coated with a dark release agent will cause cookies to over bake on their bottoms. Double stack (place one pan inside another) to end this pesky problem.
Always season new pans (before baking) by applying a thin coat of vegetable oil and placing them in a 400 degree oven for about 20 minutes. Wipe them clean, cool and then prepare the pans as usual for baking.
Cookies stick to the baking sheet when the sheet is not properly prepared for baking. Be sure that the sheet is seasoned before using, if new. Do not use detergents for cleaning. Wipe the sheet clean with a lightly greased cloth then wipe with a dry cloth or paper towel.
Cool the sheet completely between batches. Putting cookie dough on a hot or warm baking sheet will sometimes cause them to stick. Remove cookies from the baking sheet while they are still warm. Use a spatula when necessary and place them on a wire rack to cool completely.
Using parchment paper will prevent cookies from sticking and keep your cookie sheets clean.
If you like soft centered cookies, chill the cookies after placing them on the baking sheet. Bake them at a higher temperature than called for, but watch closely. Remove the cookies from the oven when they are light brown.
When cutting or bagging cookies; try to make them all the same size. They'll bake evenly that way.
Cover cookie dough between baking batches. The dough will dry out quickly and become unworkable. Cookie dough freezes well (6 to 12 months). Wrap tightly and freeze left-overs for next time.
Most cookies should bake 10 to 12 minutes. Start with an oven temperature of 350 degrees and go up five degrees until your cookies are baked 10 to 12 minutes. Longer baking times will cause the cookies to be dry. Do not overcrowd the cookies on their baking sheet. Let the hot air circulate around each cookie.
It is important to make notes and attach them to each cookie recipe that you make. Next time, you'll have the notes to refer to and your baking process will flow much smoother.