I really wish I would have realized how short my time here was.
I leave HK next week for a trip through Thailand/Vietnam and I've still yet to do about a million things on my list of things to do in Hong Kong. I spent so much time not in the city figuring that I would always have time later to find myself with no time left.
Also, bring the shoes/clothes that fit you well and if you need more, just get them copied here. I've not been able to find any shoes that fit me (size 13 4e) in this entie city, and no store can even have them special ordered and shipped for me. The clothes battle for me has been lost as well.
On the other hand, I wouldn't trade the experiences I've had here for the world. It is a very different culture than from where I'm from and even with all of the complaining about it not being like the US, it was still a great treat to get out of there and experience more of the world.
Also, if you can, try and see if you can get a multi-entry visa for China in your home country. I know a lot of my friends who were able to get multi-entry visas into China from the US, but they won't issue me one here - so I've been stuck with using double entries and paying each time I want to go shopping or something.