My mom is known for her homemade cookies, several varieties, and is always asked to bring them.
She doesn't make up recipes, she just gets them from your average cookbook, like Betty Crocker. The main secret is, she just doesn't bake them as long as the recipe says. Like if the recipe says, "Bake 16-18 minutes," she sets the timer for 8 minutes and checks on them by eye after that, until they're just barely done. They're much softer and moister than what you usually get. Of course it's not good if you like crisp, crunchy cookies.
The other thing is, we like flavorful cookies. So if it's something like gingerbread, with spices in it, we add a larger volume of each spice than they say to. No bland cookies for us!
Cookies seem to be very popular if you make less usual varieties. Like, most people do chocolate chip and peanut butter, and that kind with the Hershey's kiss on them. We do, like, pumpkin spice cookies, molasses cookies, double chocolate almond coconut cookies, that kind of thing. All pretty simple all-in-one-mix drop cookies, really.