Tangled tent guy lines are a pain. I've taken to doubling mine a few times until it's quite short and then tying a loose overhand knot. That seems to work most of the time to prevent guy line tangle. Recently friends gave us a cheap pop-up tent for our grandchildren to play in. That tent had little sewn bags for the guy lines. I have never seen them before. I did a search to see what was out there and didn't get much but it seems that Exped tents come with these bags for guy lines and they double as mini-flags so that you notice the guy line instead of tripping over it.