I've always been very particular about making cookies, whisk dry ingredients, cream butter/sugar well, often to light and fluffy; butter/eggs at room temp, weigh ingredients, don't overbeat flour, etc. I love the results. My daughter made cookies by herself yesterday. I popped in periodically to watch. I came by as she dropped the flour right into cold eggs and butter (and white sugar) that she didn't cream well first. Mixed it all. Realized she forgot brown sugar. Added that at the end. I thought it was a little gummy so I added a large tablespoon of cornstarch. Result? The best chocolate chip cookies (nice chew on the outside, soft on the inside, bendy but not soft). Really? Have I been sticking to rules that really are unimportant?
What "rules" of cookie baking do you no longer follow because you found it made no difference? I'm wondering what would happen if I just put in all the ingredients and mixed.