Arthur Frommer's Budget Travel magazine ran a contest asking for the best packing tips from readers. At this link you can find the entries from the five winners.
This is a frugal and sensible bunch, so the advice is good and it doesn't involve going out and buying a bunch of expensive travel gadgets. Some of these concern packing for kids and one involves being ready to go at a moment's notice, but they're all worthwhile.
Here's one of my favorites, since it reinforces the idea of everything needing to be worth its weight. "Bring only the beauty essentials, and look for products that have dual functions. For example, take a tinted moisturizer with sunscreen--it's like having foundation, lotion, and sunscreen all in one."