It’s important not to over-bake the cookies, so it’s a good idea to know what you’re looking for. When done, the edges of the cookies will be golden brown. You’ll notice the centers are still soft. Always leave the cookies on the sheet until it cools down. Once you remove them from the oven, the center will flatten out a little and finish baking.  The other tip I have is to invest in a nice oven thermometer to check to see the actual temperature of your oven. I just bought a new thermometer and found out my oven is cooking 15 degrees UNDER what I set it at. I had to accommodate for that.