Chubby cheeks and a slight double chin - what procedure would be best for me?

Facial aesthetics especially on young people is primarily determined by bone structure.
You don’t have an abnormal fat distribution nor do you have abnormal buccal fat pads.
Liposuction can be very effective at giving a defined jaw line especially on individuals who are chubby or overweight.
For individuals with thin layers of subcutaneous fat Liposuction is not going to have a big impact.
To make a proper assessment in regards to facial aesthetics we need to see the entire face showing a frontal and lateral view.
Most issues surrounding the lower 1/3 of the face have to do with the shape and size of the mandible especially and its relationship to the Maxilla.
Oral surgeons tend to make assessments and recommend treatments based on bone structure while plastic surgeons tend to be soft tissue oriented.
Considering that the issue is primarily based on bone structure expect soft tissue solutions to only give partial improvements.
I highly recommend people avoid having buccal fat removed sins a loss of facial volume tends to cause premature facial aging.
95% of individuals seeking Chin and neck liposuction have an under developed mandible. This typically also presents with a dental overbite occlusion, profile pictures will show the upper lip having a more forward projection than the lower lip, premature double chin and premature jowl formation.
When the mandible lacks sufficient forward projection the platysma muscle drapes the neck in a more oblique fashion.
Best,
Mats Hagstrom MD