36 and Crepey loose skin on neck. What is the best method to help this and keep it from getting worse? (photos)

A combination approach would give the most improvement. Kybella, PDO Nova Threads, Ultherapy and/or ThermiRF treatments (Venus Legacy) are non-invasive options that would do well in combination for skin tightening for the neck. VASER with ThermiRF is a great alternative for contouring and tightening the chin and neck and can be combined with a neck lift at the same time, if you're a candidate. See a cosmetic dermatologist for a long term treatment plan. Best, Dr. Emer.

Hello and thank you for your question. Based on your photograph, you may
benefit from a mini neck lift.  If good technique is used,
this can be done with minimal scarring and can result in a natural look, not
over-done look, with rejuvenation of your neck.  Make sure you specifically look
at before and after pictures of real patients who have had this surgery
performed by your surgeon and evaluate their results. The most important aspect
is to find a surgeon you are comfortable with. I recommend that you seek
consultation with a qualified board-certified plastic surgeon who can evaluate
you in person.
Best wishes and good luck.
Richard G. Reish, M.D.  FACS
Harvard-trained plastic surgeon

You have a few options. Try Botox to soften your platysmal bands and chemical peels to improve the quality of your skin and, one hopes, restore a bit of elasticity. Kybella or neck liposuction may be good options for defining the chin and jawline. I hope this helps.