When I arrived I did not want to go straight into teaching in the first crappy centre but knew I had to work and save hard to open my own.
I did
1.) Man with a van = good for about 20 -25k per month. On a good day it's easy on a bad day you have to take a sofa bed up a 12 floor walk-up in Central. If you wanted to, you could make a pretty good company here running vans for English speaking customers. You add value by speaking English and labouring, (local co..s only drive!) (Don't forget your diesel costs, if possible have friends in the NTs who can help with cheap fuel ;-)
2.) Tours and transfers = easy money and you soon have a posse of regular customers, not strictly legal but if you've got to eat....and everyone knows the score. You get customers who want you to take their dogs to the country parks, airport transfers, show their friends around - cross border is very lucrative, I hired a guy and car and still made money, it's super expensive to buy a cross border vehicle.
3.) Handyman = lol, I had all my tools shipped over from England and, you know, lots of expats can't drill a hole so you can make cash there! To be fair, I am like that now, I don't have time or will to paint so I'd hire a painter now.....anyway, if you're handy, you can make a good living.
4.) Trading = it's risky but you can go over the border, buy stuff and flog it on ebay, I didn't like this too much and feel free to PM me if you want Nokia hands free kits epads, fake iphones and so on! Maybe you'd be smarter than me at this!!
A lot of expats are complete tight asses and they will try to squeeze you for every dollar, but my rule of thumb was always never ever take a job for less than 400HKD per hour. In HK, the simplest thing can end up taking hours so you must charge hourly!! Remember it's your time not your labour that you need to get paid for! Seems funny to me now that I did that but, it got me over a hill and now things are different, plus I sure do value where I'm at now!!!
I haven't done any of that seriously for nearly two years but I still get calls and have done a cheeky airport transfer or two in the last year!!!