Use zip ties – Packing tip

Since the increase in security, airports recommend you keep your luggage unlocked because if they find any reason to check your belongings, they will be forced to break open any lock on your bags.

So, you think you have 2 options:
1.) Have multiple spare locks (which can be costly!); or,
2.) Keep your luggage unlocked and risk your suitcase bursting open with your undergarments flying (unfortunately, speaking from experience).

However, there is one more option: use zip ties to secure your zippers. Zip ties will keep your zippers closed tight, but are simple enough to cut open if security needs to check your bag.

Bonus: Not only are zip ties cheap, they come in a variety of colors, which is useful when trying to spot your luggage amidst dozens of other identical suitcases.