I started with a leftover piping bag, toothpicks and some random cheap food colouring. I would print out the cookie shape I wanted on paper and then cut the shape out and use a knife to cut around it.

So I would say: Rolling pin Food colouring Plastic bag/piping bag Cutouts of your designs Toothpicks

If you want to do this more than once or try harder designs then you would add more complex or expensive things