In 10.10 there is a bug in usb-creator that may cause your problems. Try creating your stick using UNetbootin, as was just suggested.
There are reports that you can fix the bug by opening syslinux.cfg on the USB drive and replace the following line:
ui gfxboot bootlogo
with
gfxboot bootlogo
You can use dd.
sudo umount /dev/sd<?><?>
where <?><?> is a letter followed by a number, look it up by running lsblk.
It will look something like
sdb 8:16 1 14.9G 0 disk
├─sdb1 8:17 1 1.6G 0 part /media/username/usb volume name
└─sdb2 8:18 1 2.4M 0 part
I would dismount sdb1.
Then, next (this is a destructive command and wipes the entire USB drive with the contents of the iso, so be careful):
sudo dd bs=4M if=path/to/input.iso of=/dev/sd<?> conv=fdatasync status=progress
where input.iso is the input file, and /dev/sd<?> is the USB device you're writing to (run lsblk to see all drives to find out what <?> is for your USB).
This method is fast and has never failed me.
EDIT: for those on a Mac ending up here, use lowercase for bs=4m:
sudo dd if=inputfile.img of=/dev/disk<?> bs=4m && sync
EDIT: If USB drive does not boot (this happened to me), it is because the target is a particular partition on the drive instead of the drive. So the target needs to be /dev/sdc and not dev/sdc <?> For me it was /dev/sdb .
Reference: https://superuser.com/a/407327 and https://askubuntu.com/a/579615/669976
Best Answer
if you are using ubuntu now, try the application "startup disk creator"
if you are currently on windows, i have found an application called "rufus" works very well
if you still cant get the USB to boot, it may be a problem with your bios configuration being incompatible how the USB was formatted... Such an issue woud be beyond my expertise...