Preheat the oven to 350 degrees F. Combine the flour, salt and baking soda in a large bowl. Beat the butter and sugars together in another bowl with an electric mixer on medium speed until light and fluffy. Beat in the eggs one at a time, then add the vanilla.
Reduce the speed to low and add the flour mixture in batches until just blended. Be careful not to overbeat or the dough will toughen. Stir in the chocolate chips and your choice of stir-ins with a wooden spoon until well combined. Chill the dough 30 minutes or overnight.
Shape or use an ice cream scoop to scoop the dough into 2-inch balls spaced about 3 inches apart on baking sheets. Bake until golden brown around the edges, about 15 minutes. Let cool on the baking sheets about 3 minutes before transferring the cookies to a cooling rack to cool completely.