Rolling a crust out evenly is essential for professional-looking tarts and pies. Getting a perfect ⅛" from the middle to the edges comes eventually with practice, but you can also cheat. We used a version of this in a kitchen I worked in to quickly get doughs rolled out to the same even thickness, every time. The beech rolling pin comes with rings of several different sizes (2mm, 6mm or 10mm) which can be attached to the ends, raising the pin and keeping you from rolling too thin. Which means no crusts or cookies that are undercooked in the middle and burned on the edges.
Adjustable Rolling Pin, $20 at Josephjoseph.com