What procedure will help with droopy cheeks?

The only cause of droopiness one can see in this photo are your moderate jowls; additional full face and profile photos would help. Correction of jowls with small cannula liposuction is very effective. In person or a teleconference consultation with a board certified plastic surgeon with expertise in facial rejuvenation is recommended. Good luck.

Droopy cheeks aka jowls is a function of gravitational aging in the face where with time gravity pulls both skin and soft tissue down. A facelift is a 2 layer procedure where the deep layer, SMAS, and skin is repositioned to reverse these changes.

A full-face and profile photo would have been extremely helpful here. However, from what can be seen, the simple use, in the hands of an experienced, board certified cosmetic dermatologist filler expert, of an appropriately robust HA contouring filler appropriately injected at the angles of the jaw and along the jawline, particularly in the region of prejowl sulcus, would likely, in one fifteen minute treatment session, address the jawline jowl issue and better define and straighten the entire jawline--without making the cheeks more puffy-looking.. Properly performed, this approach would yield immediate, on-the-spot results and typically engender little to no significant downtime.
You would be wise to exercise a whole lot of "buyer beware" caution when being hawked this or that fancy-named and expensive light and energy-based devices that are out there, since the hard science to back up the use of these here-today-gone-tomorrow gizmos lags woefully behind the heavy marketing hype and social media buzz to promote them. Hope this helps and best of luck.