India, Nov. 17 -- The worst travel moment is familiar to any obsessive traveller. You pull out a suitcase, brush off the dust, and there it is. The lock with a combination that has completely vanished from memory. This has happened to me more than once across many different suitcases. After a few of these moments, my family and I agreed on a 3-digit code that everyone remembers. One of us always has it ready, and we even use it for some electronic passwords. It is now our go-to unlocking number.

Before we get into unlocking a suitcase with a forgotten code, here is how to set it when the default is 000 on a new suitcase.

Most combination locks have a reset state. Look for a small recessed button or a sliding lever inside the zip pull or...