Create a Quick OSX bootdisk on USB

OSX Bootdisk

Ever need to create a bootable install USB for your mac?
Yosemite has a built in USB installer maker!
Just grab a 8GB Usb Stick and create your installer today, always good for emergencies!

The Terminal way:
Yosemite has a built in USB installer maker:
1) Download installer from app store and quit after it opens.
2) Plug in 8GB (or more) and make sure it is named "Untitled"
3) Open Terminal and copy and paste the following and hit enter
sudo /Applications/Install\ OS\ X\ Yosemite.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install\ OS\ X\ Yosemite.app --nointeraction
(this will wipe your USB drive and install the Yosemite installer onto your USB drive)
4) Wait until you see the text "Copy Complete."
Done.

The App way:
1) Download the installer from the App Store
2) Quit it after it opens.
3) Go to http://liondiskmaker.com and download DiskMaker X. Grab an 8GB USB drive.
4) Run DiskMaker to create a USB installer for Yosemite.

Install a clean OS X
1) Hold down Option and select this drive after reboot.
2) Go into Disk Utility first and re-partition the drive as 1 partition, Mac OS Journaled. This WIPES THE DRIVE, get your stuff off first.
3) Then go into the installer and install on the new partition.
Boom, clean install of 10.10.

There is a more visual guide over on osxdaily
http://osxdaily.com/2014/10/16/make-os-x-yosemite-boot-install-drive/