Facial expression wrinkles or expression lines are formed when we deliberately move and contract our facial muscles.
Over time, the repetition of facial expressions/facial distortions such as frowning, smiling, lifting your eyebrows when you talk, pursing your lips, and squinting under strong sunlight, will leave lasting and visible lines on your face.
Of course, it's impossible not to have any expressions just to prevent facial expression lines, but it's good to get in the habit of decreasing the amount of time you spend frowning especially when you are having a bad day.
Also, it is good to wear a sunglasses to protect the delicate skin around your eyes, while avoid squinting, which will in turn help keep the crow's feet at bay.
After all, we all love to delay the process of having those deep lines and crow's feet plastered on our face, right?