Preheat your oven to 375°F (190°C). Line a baking sheet with parchment paper.
In a medium bowl, whisk together the flour, baking soda, and salt.
In a large bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy.
Beat in the eggs one at a time, then stir in the vanilla extract.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Be careful not to overmix.
Stir in the chocolate chips, pretzels, nuts, toffee bits, and any optional mix-ins.
Chill the dough for at least 30 minutes (or even overnight).
Drop by rounded tablespoons onto the prepared baking sheet, leaving enough space between each cookie.
Bake for 10-12 minutes, or until the edges are golden brown but the centers are still slightly soft.
Let the cookies cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.
