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underneath my clothes, in which I store some money, my passports, and a boarding pass (although these last ones have been replaced by digital phone-based passes in the last few trips I've taken...).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, check that my computer, my camera, and my headphones are still there.
Hopefully this helps :)