I've got an escape artist (not a GSD) so he's tied out ALL the time. At our old house, he was even on a tie out INside the fenced yard, lol. He learned how much space he had. We always used the tie-out cables that are like thick wire covered in smooth plastic. They don't get snagged on stuff, knotted, or curl up. I've tried a lot of other ropes and cords and was never happy with anything else. He quickly adjusts it himself if it gets between his legs. You can get these spring snaps for the end if you think she's going to hit it and needs the shock to be absorbed.
We use this stake for the tie-out, it's the larger heavy-duty one (my dog can pull out or bend those common curly ones with the triangle on top in seconds)
When he's going on a hike, I use 5/8" biothane line but it's fairly heavy (which helps in our case as he can feel the weight of the line and understand he's still tethered).