Do NOT stuff everything into carryons. Since 9/11, they have become very strict with how much you can carry on board with you. In your carry on put a change of clothes for each person, plus essential toiletries, something to sleep in if you choose, and a bathing suit if you are going to a warm climate. Also include your camera(s), laptops, jewelry, medications and any other irreplacable items. This shouldn't be more than a tote bag or small gym bag's worth of stuff. The rest gets checked. With bag matching the chances of your bag no arriving with you has greatly decreased. Even if it doesn't arrive with you, it generally will show up on the next flight and they'll deliver it right to your hotel.
I've flown over 1M miles. I've had one bag go astray never to be found again (Untied, and I think it was pinched, as it was labeled inside and out with a paint pen), probably betwee 1-20 times the bag didn't arrive with me and was delivered within 24 hours (pretty much every carrier, United and AA seem to be the worst offenders for that), and once that a bag was ruined because someone packed soda in a bag, it leaked during flight, gooed all over and into my nylon bag, ruining clothes and bag alike (again, Untied). But when you htink about it, the odds are really very good that your bag will arrive with you. As far as things being ruined, other than aforementioned soda incident, I can only think of once, and it was my fault. On my way out the door I slipped a bottle of nail polish into a ziplock bag, and then into the front pocket of the bag. I meant to pack it either into my carryon or the inside of the bag before I checked it, but forgot. It ended up cracking. It made a small hole in the ziplock, but luckily very little spilled, and none left the pocket.
Anne