2. Insert USB (at least 8GB). No need to clean or format. Installation will format this drive. Take note of the name of the drive via Finder (under devices) or type mount from Terminal and take note of the /Volumes/name_of_usb_drive
3. Open Terminal via Applications->Terminal
4. Type the following from the command line. Replace [name_of_usb_drive] with the name of the drive from #2.
sudo /Applications/Install\ OS\ X\ Yosemite.app/Contents/Resources/createinstallmedia --volume /Volumes/[name_of_usb_drive] --applicationpath /Applications/Install\ OS\ X\ Yosemite.app --nointeraction
5. You will see something like the following, follow instructions and/or let it finish.
"Erasing Disk: 0%... 10%... 20%... 30%...100%...
Copying installer files to disk...
Copy complete.
Making disk bootable...
Copying boot files...
Copy complete.
Done."
6. Reboot. Press Option key during boot and choose Install OS X Yosemite drive upon boot.
