Crepey/Loose neck skin in 20s. Any suggestions? (photos)

"Injecting soft fillers like Belotero in this area can reduce lines, wrinkles and folds as well as improve skin texture with long-term collagen production. Fillers are being used more frequently to contour and lift rather than solely line fill. Of course, fillers are best used in combination with lasers and microneedling​ with PRP to get the optimal outcome.

I suggest getting a formal evaluation with a cosmetic dermatologist to create an individualized treatment plan that works for you. Best, Dr. Emer"

You need to stop smoking immediately.  It is terrible for you for so many reasons.  You will age much more rapidly.  You are already seeing the smoking related changes, and you should expect the wrinkles to get a lot worse in the near future if you don't stop the smoking.

Best non-surgical options to improve one's appearance is to start the following:avoid smoking. Smoking prematurely ages the skin and facial tissue. Smokers can look much older than their chronilogical agedrink plenty of water. The skin is mostly water and most patients don't keep themselves hydrated sufficientlysun protection. All patients, including darker skinned patients, should be using sun block daily to protect from UVA and UVB raysSurgical options for loose neck skin in younger patients including possible liposuction or chin augmentation. A lower facelift or neck lift surgery for loose skin is normally not performed for patients under 40 years old. If you haven't already, then speak with a plastic surgeon to perform a comprehensive examination and review options with you.Best,Dr. Chaboki