Original picture
final effect
1. Use the pen tool to outline the eyeliner and double eyelids, and fill them with dark colors to make the outline of the eyes more obvious.
2. To deal with the eyelashes, use the pen tool to draw out the arc from left to right on the right side of the eye, and reverse it on the left eye. Here is a description: When using a brush to stroke, first set the size and pressure of the brush, and extend the part beyond the eyes appropriately. After tracing the edge, use the eraser tool to erase the excess part appropriately.