I have followed Debian's instructions (
https://wiki.debian.org/DebianInstall#Creating_a_Bootable_Debian_USB_Flashdrive) for creating a bootable USB stick but it fails to boot on my UEFI-only laptop, that is the USB stick is not recognized at all. In contrast, I am able to create the same for Knoppix 9.1 following their instructions (ie. using flash-knoppix) and it boots just fine.
Some folks on the debian-user mailing list helped a bit with some ideas and think that the issue *could* be due to the architecture of the EFI program that is (or is not) included in the EFI boot folder of the resulting USB stick.
Checking on that idea, I see that the resulting Debian USB stick I have only has a 32-bit EFI program in its boot folder. Should there also be a 64-bit version there? FYI, in contrast, the knoppix USB stick has both 32-bit and 64-bit programs.