Make sure all of your macaron shells are paired.
Between two pieces of parchment, roll out your cookie dough to the thickness you'll want it in the center of your cookie. Leaving the parchment on it, set it on a tray and put it in the fridge or freezer to firm the dough, this makes it easier to handle.
Once the dough is firm, cut circle with a small circle cutter. Lift the pieces with your fingers or an offset spatula to transfer to one side of each cookie. Alternatively you could roll balls of dough and flatten them.
Seal the cookies with the top cookie. The closer the dough is to room temp, the easier it will be to seal.
Store in an airtight container in the refrigerator until ready to serve.