TT blades are pretty cheap, good training gear help keep your blades in one piece, and not going too far too fast helps too. Can't say as any of my students have ever broken a set learning, but I don't let them just fire it up and fly around. they stick to a pretty tight regiment. Once they start getting better, they progress to the next step. If you try too much too fast, you will break them. I got lucky, never broke a set till I started looping, but that was 20 years ago long before glass blades and gyros.