Saturate the cotton ball with fingernail polish remover. Remove all traces of polish from your fingernails so they’re ready for a brand new polish job.
With the fine side of the fingernail buff facing down onto your nails -- often the pink side -- buff them thoroughly to make the nails smooth.
Swipe your nails one more time with a smidgen of fingernail polish remover to remove every trace of dust and debris you created with buffing.
Choose a nail polish for the base color of your fingernails. It can be light or dark -- whatever works to create the look you want. Apply the nail polish in a thin and even layer, let it dry and add a second coat. After the second coat dries completely, you’re ready to create the diagonal lines.
Load the nail-polish brush with the accent color of your choice to create a diagonal line. Figure out where you want the line to go across your nail and then lay the side of the brush across the nail at just the right spot. Carefully pull the brush across your nail to make the diagonal line from one edge to the other edge. Fill in the area on the other side of the diagonal line with color after making the line. Let the accent color dry completely.
Make similar lines on each nail, taking your time to make each diagonal neat and tidy.
Add any additional accents to your nails after the diagonal lines dry. Let the last coat of color dry completely before you finish your nails.
Apply a clear topcoat to each fingernail to help the design last and resist chipping.