Preheat your oven to 375°F (190°C). Line baking sheets with parchment paper.
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.
In a separate bowl, whisk together the flour, baking soda, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Do not overmix.
Stir in the chocolate chips and your chosen add-ins until evenly distributed throughout the dough.
Drop rounded tablespoons of dough onto the prepared baking sheets, leaving about 2 inches between cookies.
Bake for 10-12 minutes, or until the edges are golden brown and the centres are still slightly soft.
Let the cookies cool on the baking sheets for a few minutes before transferring them to a wire rack to cool completely.