I typically use Rufus or Yumi for my USB booting needs, along with BootICE to edit BCD files to and fix the MBR of a non-bootable USB stick. all three are freeware, and are very handy utilities to have.
BootICE: https://sites.google.com/site/gbrtools/home/software/bootice-portable/bootice-downloads
YUMI: http://www.pendrivelinux.com/yumi-multiboot-usb-creator/
Rufus: https://rufus.akeo.ie/