**Straps**
Other answers have touched upon recommendations I'd do myself: put valuables in in your carry-ons and be prepared to not get your checked-in luggage (even though it is an extremely low probability). Having colored strings or even straps that completely surround the luggage could help. **You could even write on or print on a nylon strap** your name or some other blatantly obvious identifier.

**Insurance**
Another option that doesn't answer your question directly but may assuage your fear is **travel insurance**. This way you can replace your late or lost luggage.

**Bag management**
Another consideration to avoid robbery is to **not leave your most valuable objects alone if you go to the airplane bathroom**. Or at least have a plan. I feel a bit ambivalent about bringing stuff to the airplane bathroom, because I don't want to bring a whole backpack with my laptop and whatever into the airplane bathroom. I feel weird about it; I don't want to make other passengers nervous, if that makes sense (this may be a 'me' thing; I wonder what others on this site think).

So what I've come to do is to have multiple 'mini bags'. I have a hidden ultra-thin fanny pack that is hidden underneath my clothes, in which I store some money, my passports, and a boarding pass (although these last ones have been replaced by digital phone-based passes in the last few trips I've taken...).

I also have a travel toiletries bag, which is just a big zip-loc. This bag exists in case I have an absurdly long flight or layover, or in case my luggage never makes it home (insurance notwithstanding).

Finally, I have a bag inside of my backpack. It's a bag made only of cloth, so that it can fold and not take space. I *usually* use it in airports to leave my heavy backpack stationed with a *trusted* friend, while I wander around the airport in search for food or a bathroom. But I *could* put stuff in it and take it to the airplane bathroom with me, leaving my backpack under the seat in front of me in the meantime.

However, what I actually do when I go to the bathroom (and this is the "plan" that I mentioned earlier), is, once I'm back, that my computer, my camera, and my headphones are still there.


Hopefully this helps :)