My friend calls it the under-the-bed check. I open each cabinet and leave them dangling out, as I pack. It's OK to be paranoid about leaving stuff behind.
The Wall Street Journal has a handy dandy tip on remembering to grab your valuables, though it actually comes from British Airways employees who do the stuff all the time:
British Airways, which collected tips from its staff, suggests placing a shoe you plan to wear on flights in the room safe with your passport. That way, you'll remember to clean out the safe when putting on your shoes for the trip home.
Now just don’t forget your shoes. This tip is definitely not for the absentminded.