What is the best way to get rid of a double chin?

Every time I take a picture, my jawline looks blurry, and even if I slightly bend my head, my double chin becomes more prominent, which is stressful. So, I've been looking into ways to get rid of my double chin these days, but I've tried everything from exercise to massage, but nothing seems to be working, so I don't know what to do.
Does anyone have any proven double chin reduction methods? Do things like massage or gua sha really help? Are there any dermatological procedures that can help with double chin reduction? I'd appreciate any information.