The best options for installing Live ISO's to usb are...
1.
Refracta2usb (unetbootin not really recommended any more)
2. use the dd command to copy an iso-hybrid image to the stick
3. set up the usb stick manually - see these guides:
pendrivelinux,
Arch wiki,
manuelbua
older guides -
http://linuxconfig.org/... or
http://brskari.wordpress.com/...
Windozer users can try out
LinuxLive USB Creator http://www.linuxliveusb.com/
or
YUMI which can put multiple distro's on a usb stick
http://www.pendrivelinux.com...
or
XBOOT https://sites.google.com/...
or
SARDU -Multiple Linux Live
http://www.sarducd.it/linux
Refracta2usb
download the deb file and run...
to install it and its dependencies in case not installed
To run the installer, plug in the USB stick but don't mount it (so unmount it if it aut0-mounts) and then you can either set up the partitions on the stick, FAT32, boot flag on for the one with the ISO.
Further methods are explained in the help, such as making a partition for persistence -so that a Live session can keep record of changes to system or config,
but the simplest way is to just create from unpacked ISO and you will need to select the correct live.cfg, vmlinux and initrd.img files.
A pop-up shows how the grub menu will look and you can rearrange any items, such as the live option that appears last.
When the main menu pops up again you can click exit.