It's been a very long time since I've looked into fiber optics, however working with rope it's important to watch the tension in your hands. You are worried that you might drop it or that someone might see inside your hands, but you can relax, open your hand more and it will draw less suspicion (the picture attached is his dirty hand from his video, See how open it is?). A second thing you can try to do more is flash your hands when they are clean and you can do so. By doing it every so often, it can help them feel like they have seen both hands empty. Also a third thing it watch your eyes and focus. When learning, we have a tendency to look at our hands to make sure we are not flashing. This is okay and important at first, however the problem is that our eyes draw so much attention! So start by watching your hands, but then move to a mirror and watch your hands int he mirror. It will help draw your eyes from habitually looking directly at your hands. Then switch to a camera and practice doing the routine and looking directly into the camera. This will help form a habit of making eye contact with people (You can then review the footage to see if you flashed). I am pretty confident that by working on these three areas that you will gain the fourth most important piece which is confidence in the effect. FO is a fantastic effect. Don't be discouraged by being caught or called out. Done well, the effect is strong. As you improve and mater the handling through performing it many many times, then you will be confident enough that you won't need to watch your hands and will handle the ropes in a carefree manner. Keep it up!