Format a 8GB+ USB with GUID partition mapping and name it Install.

Insure the OS X Yosemite.app is in your Application folder.

In terminal run the following script.

sudo /Applications/Install\ OS\ X\ Yosemite.app/Contents/Resources/createinstallmedia --volume /Volumes/Install --applicationpath /Applications/Install\ OS\ X\ Yosemite.app --nointeraction

This will take several minutes so be patient, the script will notify you when complete.

Now Install Clover r2696 (or newer) to the Install USB. Clover r2953 or newer Recommended! 
Copy FakeSMC and Network kexts to /EFI/Clover/kexts/10.10  (you’ll have to create the 10.10 folder}

Boot USB to Clover, highlight "Install OS X Yosimite" and hit the spacebar, choose "with injected kext”

and install Yosemite. Re-boot to USB and select your SSD or HD, hit the spacebar and again

choose “with injected kext” to complete the installation.

Install Clover to your boot drive. install your kexts to S/L/E or use Clover to inject kexts from EFI/Clover/kexts/10.10

Done

EDIT: For anyone having a problem with this process:

You might try using the HFSPlus-64.efi (Google it) rather than VBoxHfs-64. Also be certain you're booting from a USB 2.0 port.

EDIT: you might also try the latest Clover version r2957

https://www.dropbox.....7.pkg.zip?dl=0 as it contains a new version of VBoxHfs-64.efi