Did this in post 29 of this thread, result is:
http://mybroadband.co.za/vb/showthread.php/616101-How-in-the-hell-do-I?p=12622275&viewfull=1#post12622275
*edit*
Disregard the fact that the instructions for installing TWRP refer to an earlier version, I was just using them as a basic template of what to do.
Now before we continue make sure the omni rom is on your SD CARD!! not internal, but SD CARD, with gapps.
Awesome, now don't worry, if fastboot didn't detect device correct then obviously it will not flash.
Now use the following commands:
fastboot flash recovery recovery.img
Make sure the twrp recovery.img is in the fastboot folder to enable flashing.