How to Protect Your Baggage from Theft
Keep your most valuable items at the bottom of your carry on in order to reduce easy access for a would-be thief.
When possible, place carry on items under the seat in front of you, where it is more difficult for someone else to access.
Checked baggage has to be personally identified by the passengers before it is loaded on the aircraft. Wherever the boarding is through aerobridges, passenger and baggage reconciliation is done through an internal matching system instead of physical baggage identification.
If your flight stops at another airport before continuing you are often given the option to take a break in the airport terminal. If you do, bring your carry on with you. Otherwise, you have provided a thief with an open invitation to steal.
Replace the locks that came with your suitcases with a stronger lock. A combination lock is preferable so that you don't have to worry about lost keys. Consider this for carry on items as well.
For checked in luggage, add a few strips of colorful tape like electrical tape or hockey tape to help indicate whether your luggage has been broken into if the tape is all torn.
Wear a waist pack of backpack. It's more difficult to cut or unbuckle a waist pack versus a purse, and it will protect your wallet, jewelry, checkbook and other small items from theft.
Wearing a neck pouch (to hold documents like passports and tickets) that can be tucked under your shirt while you are sleeping is a good option.