V Shaped jawline - best procedure? Botox, Radio Frequency, or Ultherapy? (photo)

From your minimal picture- you are a candidate for all 3 of those procedures. The benefits and risks vary- botox, lasts about 4-6m and will slim your lower face, ultherapy or RF treatments will tighten the skin and will last a few years and for the puffiness around the mouth- you can consider buccal fat removal. More pictures would be beneficial and you will get more information at a consultation. 

Looking at your picture, the only reason I can see for you being puffy around the mouth is that you appear to be quite young. Al the techniques developed for enhancing the shape of the jaw are designed for and work better with older faces after time had its way with it. Please learn to enjoy the pretty face you were blessed with.

Thankyou for your question.
Options for jaw slimming are multiple.By far the quickest and easiest way is by relaxing the chewing muscles with botox. This will also be the most effective provided you have some evidence of masseter hypertrophy or oversized chewing muscles which is not able to be fully asessed from your photo however from the little I can see I believe you may be a good candidate.
The puffiness around the mouth I believe you are referring to are jowls which are made up of fatty tissue and skin. Treating masseter hypertrophy with botox can sometimes  make jowls worse as it reduces bulk under the skin which may be supporting the jawline however in a person under 40 this is usually not an issue.
Again this needs to be assessed in the flesh .
Jowls can be reduced by a number of ways including direct injections of lipodissolve to dissolve the fat permanently, filler along the jaw line behind the jowl ,and into the area in front of the jowl to disguise it , filler  into the cheek and into any cheek hollow to create lift , or even liposuction . 
Of course the overall shape of your face needs to be assessed.If it appears that the lower third is out of proportion to the upper 2/3rds, this can be reversed by filler into the cheeks, temples, eyebrows and temples .The face appears slimmer at the bottom if the upper part is enhanced. Chin filler increasing the downward pointing part of the chin and creating more midline fullness can also  enhance a more upside -down triangular shape 
Radiofrequency or ultrasound devices to create lift are a good treatment to add but less dramatic than all the procedures I have discussed .
Hopefully you are a littel  clearer regarding the options however you do need a good clinician to guide you . Ask for pre and post photos