After seeing this Youtube video on how to open a locked suitcase without a key, I would not invest in locks or zip ties, as I fell they do not discourage theft. Thieves know all the tricks out there, and if they are to hit you, they will. No lock would prevent them from it. https://www.youtube.com/watch?v=qDgr9zD4ZU0

I would be more careful as to what I packed in my suitcase and try not to attract attention to myself or to my belongings. Look at what the OP lost, some travel sized personal toiletries, probably valued at about $20 or so maximum, yet they got hit. Its best not bring along that which you do want to loose or would cost a lot to replace.