**NO NEED TO COPY TO APPLICATIONS FOLDER – CAN RUN DIRECTLY FROM MOUNTED DMG!
***CAN INSTALL TO A VOLUME ON THE USB (eg: Use 8GB of a 64GB usb, by first partitioning it.
Assuming that you have the OS X Yosemite installer in your Applications folder and you have a Mac OS X Extended (Journaled)-formatted USB drive named “Untitled” mounted on the system, you can create a Yosemite install drive by typing the following command into the Terminal.
The command will erase the disk and copy the install files over. Give it some time, and your volume will soon be loaded up with not just the OS X installer but also an external recovery partition that may come in handy if your hard drive dies and you’re away from an Internet connection.
