In my experience, you want to do it with both wheels on the ground or on ramps. If you jack it up with the suspension fully extended on one side, the sway bar puts tension on the links, so they'll feel tight. At normal ride height, there's little to no tension in the link, so you can find the play. I think that twisting is ok, as long as it feels tight. If it is loose or has rattle in it, it needs to be replaced.
I think if you evenly jack up the front, like putting the front on a pair of jack stands, there will be no tension either.