DIY Door Lifting support for floor jack

[gzig5]

I know there are a couple commercial fixtures that attach to a floor jack and help get a door lined up for mounting the hinges.  I'm not seeing any DIY versions and I know they have to be out there.  I have a trans jack or big floor jack to use.  Thought the adjustments in the trans jack might help.  So anyone have a fixture they've seen or come up with to share a pic or two of?  I always like to see a sample before I go about slapping something together. I've got a couple ideas using wood 2x4 but I have plenty of square and round tubing to weld with too. Something along these lines.