Over the years, the skin on your neck may start to sag. An incorrect posture, where you look down at your phone screen, can create neck lines. These lines may also be inheritable. On top, excessieve sun exposure leads to accelerated skin aging. The skin on your neck can become wrinkled and saggy, making you look older. Fillers and biostimulators are an effective way to smooth out and tighten your neck.