What is the best filler for "hollow" cheeks? What can be done for "turkey neck" without surgery?

Thanks for your question, Kim.  There are injectable fillers like Juvederm Voluma or Radiesse that can be used to add volume to cheeks.  There are skin tightening devices that use ultrasound (Ultherapy) or radiofrequency (i.e. Thermage) and these could be used in some cases to tighten skin around the neck.  However, what you really need is an in person consultation with a well trained and experienced physician who can evaluate your individual case and tailor a treatment plan just for you.  That is your best course of action. Good luck to you!

Its not possible to provide you a specific or relevant comment about cosmetic options for your neck if you won't post at least one picture. I would suggest an in-person consultation with a facial plastic surgeon in your area. Without surgery your results will be very conservative to minimal to non-existent especially as you have described yourself.