My wife is not into sail tweeking but likes to sit in the cockpit (which I am just fine with, happy that she comes along) and of course someone sitting in the cockpit is either helping with the sail trim or is in the way. So.. she runs the jib sheets. What I did after a while was to put a black ring using a sharpie around the jib sheet line where it just exits the deck cleat. So when we tack, she just pulls the jib sheet line so that mark is just aft of the cleat. One size doesnt fit all in this case and I can come back a tweek the line (or she can) but for more relaxed sailing, that single mark often works just fine. The shapie mark last about a season which is sort of good since I moved the "nominal" spot for the jib car this year vs last and that changed things a little. We have overall liked that mark on the sheet line although its not going to be of any value for most crew. Helps in my case however and I think I will also look for some of that paint.