I'm real finicky about my props. God forbid I bang or bend one, I get all freaked out ;p. The reason is simple: I know how critical they are to flight performance *and* reliability. One could lose their entire investment and/or cause damage to property or people, all due to an $8 prop. Here are my rough conclusions so far: 1. Examine props regularly for cracks in the center, just to be safe. I've never seen this happen, but it seems like it could. 2. Take them off before putting your quadcopter into a case. After all, it takes only a few seconds to remove or install the self-tightening props. Don't be lazy. It's not worth the risk. 3. Never, under any circumstances, use cheap generic props. Make sure yours say DJI, or are manufactured by a company you really trust. Those 'XOXOXO' brand have entirely different rigidity and I wouldn't trust them at all. Be careful, as often the manufacturer of props isn't made clear on order pages. 4. Carbon fiber props? I haven't tried these. Some people swear by them. If you do go with them, again, pay attention to #3. They also seem inherently more dangerous to me, so make sure you've got some good liability insurance in case you cut off someone's finger, etc... 5. Balancing? I dunno. I never have fooled with it. Good props should come pre-balanced and remain that way unless they are damaged. 6. Immediately toss out any damaged prop. I actually would be hesitant about using any prop that has been involved in a crash, but that may be a bit excessive.