There's actually a science to trimming nails. Nails have a grain, so bidirectional trimming is definitely a no-no that leaves them slightly ragged. Instead, always file your nails in one direction, from the bottom edge to the center top. Alternate from one side of the nail to the other until you create a smooth, rounded curve. If your nails are a lot longer than you want them to be, trim them with nail clippers before you start shaping them. It will save time. As you shape your nails, work to create a modified crescent with a slightly flattened top. It's a popular, flattering and maintenance-free nail shape.