Since don't keep a lot of your daily-use valuables in a safe at home, it's easy to forget them when you toss them in a hotel safe. The Wall Street Journal suggests putting the shoes you plan on wearing for the flight home in your safe to help you remember to clean it out.
The tip comes from a list collected by British Airways staff, and it's a good way to remember the items you keep in the safe. If you've had the misfortune of getting all the way to the check-in at the airport only to realise your passport and keys were still sitting in the safe at the hotel, then this is a handy way to help you remember to grab them before you leave. Hit up the Wall Street Journal article for a huge list of other travel tips. Of course, this won't work if you're a compact traveller and only have one pair of shoes with you. But you could put the socks you'll wear on the last day in there — Oz ed.
25 Ways to Make Travel Easier, Starting With a Single Shoe [Wall Street Journal]