For smooth lines and easy application, invest in a nail brush (or toothpick!) to create the half-moon shape you desire. If you have a shaky hand, start by adding dots across the base and then connect them to create a curved line.
If a brush or toothpick proves too difficult, you could also opt for hole stickers. Cut the paper reinforcements in half and place them at the base of your nails to create a half-moon shape. Secure them tightly so there are no gaps and then apply color.
Next, polish the rest of the nail with your color of choice. If you opted for the hole stickers, gently remove them while the polish is still wet to avoid lifting. The result: a beautiful half-moon mani.