It is easiest to roll flaky pie dough when it has been refrigerated for 45 minutes, at which point it will be chilled sufficiently but still malleable. Dough rolls best at 60°F/16°C. If there is an area in your house that is close to this temperature, such as a wine cellar or pantry, it is fine to leave it there for several hours before rolling.
Brush off any excess flour on top of the dough after shaping it because it will taste bitter after baking.
To cut a round disc of dough, use an expandable flan ring, which functions like a large cookie cutter, or make a cardboard template the size of the disc you need and use a small sharp knife to cut the dough. You can also use a cake pan of the appropriate size: Cover the dough with plastic wrap to keep the cake pan from sticking and then set the pan on top of the plastic wrap. Lift up the plastic wrap and cut around the edge of the pan with a small sharp knife. Press down lightly on the pan when cutting to keep it from moving.
I have developed a unique and effective way of fitting tart dough perfectly into the pan (see photos). For a 9inch tart pan, invert an 8inch cake pan onto a work surface. After removing the top sheet of plastic wrap and cutting the disc of dough, use the bottom sheet of plastic wrap to lift the dough and set it, plastic side down, over the 8 inch cake pan. Smooth down the sides so they will fit into the tart pan. Place the removable bottom of the tart pan on top. Then carefully place the fluted ring, upside down, on top. Place a flat plate or cardboard round over the tart pan to keep it from separating and invert the pans. Remove the cake pan and carefully peel off the plastic wrap. Gently ease the dough down to reach the bottom and sides of the pan.
Rolling sweet cookie tart dough is the fastest and most even way to line the tart pan; however, it is also fine to press the dough into the pan with your fingers. Once the dough is distributed in the pan, line it with plastic wrap and use your fingers or a flat-bottom measure or custard cup to smooth the dough over the bottom of the pan. To make a beautiful border, be sure to press the dough ⅛ to ¼ inch higher than the sides of the pan.
If time allows, after lining the pan and crimping or fluting the edges, cover the dough with two layers of plastic wrap and freeze overnight before baking. This will ensure that the border will have the best possible shape.