Cut the prepared croissant dough in half. On a floured surface, roll out one portion of the dough into a large rectangle about 1/4" (6 mm) thick. Use a large, sharp knife or pizza cutter to trim straight edges on the rectangle, and then cut out 8 elongated triangles. (My triangles in the photo weren't cut evenly, so I ended up with a few croissants that were a bit smaller than the others.)
Roll up the triangles from the base to the tip, and transfer the croissants to ungreased baking sheets with rims. (I use parchment paper for easier cleanup.) Leave ample room between the croissants for expansion.
Cover the croissants loosely with plastic and leave to rise for 1 to 2 hours, until the dough is quite puffy.
An alternate fold: To form a a bent crescent shape with tapered edges, make a small slit in the base of the triangle. Roll up the triangle from the base to the tip, and bend the edges downwards.