Disclaimer: I am answering my own question.
I need to wipe my Windows laptop's internal hard drive. I find DBAN per How-To Geek's recommendation, but I am having trouble installing it on a 64GB USB flash drive and make it bootable on an UEFI-equipped PC.
After downloading DBAN's ISO file from SourceForge, I first tried ImgBurn per the recommendation of an earlier How-To Geek article. I quickly realized that I misread that article because ImgBurn only burned to optical disks.
Next I tried was a tutorial from Tom's Hardware. That article suggested using Rufus. It did not specify which file system should I format the flash drive to during Rufus' burning setup, so I selected FAT32 as shown in the screenshot. However, since the ISO selected in the screenshot was "FreeDOS", the screenshot might be for illustration purpose only.
In the UEFI, the burned flash drive was shown as "[UEFI] followed by the flash drive's name". I moved it to the top of the boot order and tried to boot, but it did not work.
I ran "clean" in diskpart and reformatted my flash drive with 512MB of space formatted as FAT and the rest unformatted. However, when I ran through the burning process again, Rufus insisted to format the entire drive for me, and I could only choose FAT32, not FAT. I restarted and that unsurprisingly failed to boot.
Next I came across this high-ranking (in Google search results) article from a website called Pendrivelinux.com, offering a software download called "Universal USB Installer". It did not seem to be an open-source software so I was a bit wary of it. But since I would be wiping my hard drive anyway I downloaded it and installed it.
The good thing about this software was that formatting of the flash drive was now optional during the burning process. So I reformatted my drive to FAT and burned DBAN's ISO to it, all without issue. But it still failed to boot when I restarted.