I have recently returned from an independent trip to Langkawi (Malaysia) unfortunately my case didn't make the connection at Kuala Lumpur, luckily it was flown over on the next flight and delivered to my hotel. But it did highlight to me that I'd never considered that my case going astray and having to describe it; I knew the colour and how much it weighed, but the make, size or distinguishing features! it had never occured to me to carry those details or how to convey those details where english might not be the first language.
I now have a picture of my case as well as details of dimensions and make stored in my phone, just in case. On my last trip with JY a member of the group had their case go astray and our tour manager Kim Clark was excellent in sorting it out with the airline and finally reuniting them after a few days, but anything we travellers can do to ease the process must be a good thing, so I'd recommend doing as I have done and storing a picture and the details just in case the worse happens, and pack a few essentials in your hand luggage.
Tim