Unfortunately, without photos that show what kind of wrinkles or sagging you have i can only comment in the most general ways, For example, for horizontal "necklace lines," superficial injections of Botox alone may be sufficient to improve them. If still necessary, a low viscosity, cohesive, malleable HA filler may be added for further elevation and smoothing of the neck. If you have sagging of the upper neck, a robust HA volumizing filler may be needed to better define and straighten the jawline, which then can secondarily improving sagging of the under chin and upper neck regions. If a deep hollowing is present in the center of the neck, the use of a robust HA lifting filler appropriately in injected in the proper location can help to draw the sagging neck upward and thereby diminish this problem. If this is just a superficial wrinkle, then a series of professionally performed manual microneedling sessions (no need for the added expense or risks of RF microneedling) may be all that is required. The bottom line is that if you are looking for simple solutions to avoid expensive, invasive surgeries, you would be wise to consult with an experienced board certified cosmetic dermatologist filler expert and best of luck.