If false eyelashes need to be shortened, they should be cut individually to different lengths. If all the lashes are cut to the same size, they look unnatural. Trim each lash at an angle using small scissors, varying the length slightly from lash to lash. The longest lashes should be at the outside corners of the eyes.
To determine the approximate length of the new lashes, they should be compared to the natural ones and trimmed accordingly. False eyelashes should not extend far beyond the length of a person's own lashes. Too-long fake lashes cause eyes to droop, which ages the wearer.
Sometimes a set of false eyelashes is too wide to fit across the eye, so the lashes need to be made more narrow. They should be snipped to the desired width, starting at the outer edge of the lashes. Another way to cut eyelashes is to turn a full set of false eyelashes into small clusters. These lashes are then used to fill in specific areas where the natural eyelashes are especially thin.
Typically, eye makeup is applied after the false lashes are in place so shadow, liner and mascara are not smudged. A coat of mascara, in particular, helps fake lashes mix in with their natural counterparts.