In a large mixing bowl, combine the flour, baking soda, and salt; set aside.

In another bowl, cream together the butter, brown sugar, and granulated sugar until light and fluffy.

Add the egg and vanilla extract to the butter mixture, mixing until well combined.

Gradually add the dry ingredients into the wet mixture, mixing just until combined.

Fold in chocolate chips and any mix-ins you choose.

Cover the dough and chill for at least 45 minutes, or up to 24 hours.

Preheat the oven to 350°F (175°C) and line baking sheets with parchment paper.

Scoop large portions of dough onto the prepared sheets, spacing them apart.

Bake for 12 to 14 minutes, until the edges are set and the centers appear slightly underdone.

Remove from the oven and let cookies cool on the sheet for a few minutes before transferring to a wire rack.

While the cookies are still warm, you can press additional chocolate chunks or sprinkle toppings like crushed candy canes or festive sprinkles on top.

For extra decoration, drizzle with glaze made of powdered sugar and milk or orange juice after they cool.