Take butter from the fridge and bring to room temperature.
Preheat oven to 325°F.
Prepare your cookie sheets, line them with parchment paper or a non-stick baking liner.
Set up cooling racks.
Stir together flour and salt in a large bowl.
In your mixer cream butter until fluffy, approximately 2 minutes.
Add sugar and continue to mix on medium until very light in colour and fluffy, approximately 3 minutes, scrape down sides of bowl as necessary.
Add flour mixture, mix on low until the flour is just incorporated.
Put dough in ball and wrap with plastic wrap. Let sit for 15 minutes to rest.
Once dough has rested, on lightly floured surface roll out dough to 1/4 inch thickness.
Using floured cookie cutters, cut out shapes and place on prepared cookie sheets. (If using sprinkles place on cookie in centre, see my heart cookies in the photo.)
Bake for 13 to 15 minutes.
Let cool completely on wire racks.
Decorate them with coloured sugar sprinkled on top or melt some chocolate and pipe on to the cookie.