Comes with experience. The pressure you exert will be great on the cards when first learning the moves. Because your body doesn't know the exact pressure to exert to execute the move. Just like the Shapeshifter, it's all muscle memory. In time you barely notice a change in deck beveling and deck condition after a few springs in a row. If after a rough session, a good way to reshape the deck is to pressure fan, cut, pressure fan, cut, repeat. It'll bend all the cards the same way again to help keep the deck from crimping or bowing.