I highly recommend the little stone chops with names translated into Chinese. Usually they sell little sets (box with chop, and paste, carving included) for about US$10. Kids love them because they can decorate their homework and personalize their paper items, and business partners love them on their desk. It's like an office seal. I got my old boss one of them (but a little higher quality than usual) and he loves using it on his office documents and thank you notes to clients.
Also, boxed tea is a great gift esp if you're going into the US, since tea is not taxable no matter the cost/value.
Linen coasters and placemat sets are also a very traditional gift.
Yue Hwa is a very reputable shop and you can shop confidently there
Shanghai Tang is very expensive but much more refined for silver plated items, fashions and apparel.
The lanes are alsways good for smaller souvenir shopping.