What is the most effective nonsurgical alternative to a facelift?

An in person consultation is best, but based on the described concerns you will likely have the best outcome from a combination of treatments. HA fillers are a great option to add lost volume and define facial contours. You can also explore longer lasting options such as Sculptra. Morpheus8 is a minimally invasive treatment that combines RF technology with microneedling to improve overall skin tone and texture. I've included a video I hope you find helpful.

Morpheus 8 is a non-invasive skin and soft tissue tightening treatment that is consistently amazing in our patients. We use the Morpheus to exact fractional induced RF into the skin or tissue in order to tighten collagen and stimulate contraction of the tissue. For acne scars, it is quite useful to build collagen in patients who have atrophic scars but is not very productive for ice-pick scars which require TCA Cross. For tissue tightening, Morpheus is ideal for the face and neck and we often combine it with CO2 laser or Ultherapy to further enhance results. Chemical peels and skin resurfacing should be done at least 5 to 7 days after, but can be performed earlier, depending on treatment severity. Avoid exfoliating skin treatments before Morpheus and expect a period of 2-4 weeks for skin contraction to set in.

Best,
Dr. Karamanoukian
Realself100 Surgeon

FaceTite can internally tighten the skin in the lower face and neck. After all the skin has been heated and contracted, we shape the neck with liposuction to give definition and remove stubborn pockets of fat. In one quick treatment, we can tighten skin, remove fat, and contour the lower face, jawline, and jowls with only a weekend of downtime. Keep in mind that combination approaches will give you a more significant improvement as opposed to a single procedure. I recommend getting a consultation with a board-certified cosmetic dermatologist and facial sculpting expert. Best, Dr. Emer

Hi there! Thank you for the question.
Re-volumisation using hyaluronic acid based dermal fillers are great when addressing volume loss and hollowness without the need of a scalpel. Using appropriate techniques, dermal filler can be used to help treat the underlying features of an aged face leaving a natural looking and refreshed appearance helping turn the clock back. Personally I use the Juvederm vycross range with excellent results. 
I hope this helps and good luck!

A combination of fillers for volume restoration and non surgical tightening like Ultherapy would help.  There are a number of other skin tightening treatments that may help but the results are not comparable to surgery.