What dermal fillers or procedure(s) would make the biggest difference in facial harmony?

I think it's really up to you to explain to us what it is that you don't like about your face as there really isn't anything that's out of ordinary, because everyone has a different face since their genetic makeup is completely different. The only thing that I could recommend, would be to create less of a pointy  chin and more of a square jawline that is still feminine. This can be done with either your own fat which will give you a natural and permanent result or a number of fillers that are available on the market today. Most fillers will give you the same results lasting anywhere from 6 to 12 months but make sure you go to a plastic surgeon who understands your needs and requirements, and has a good reputation. I hope this helps and good luck from New York City plastic surgery

Based on the photos, I think you would benefit most from filler injections to the lower face. I would recommend treating the lateral chin, prejowl, and marionettes lines using an HA filler like Restylane Lyft or Restylane Defyne. I would also add a little filler to the upper lip and possibly the cheeks. The best thing for you to do is schedule an initial cosmetic evaluation with an experienced aesthetic physician in your area.