To answer your question.

I'm not that well-off, as u can tell above. Also rather average salary for a graduate couple, would not say the job pays that well. Family is also average, we acquired both properties ourselves, did not borrow from relatives.

My assets were acquired the boring way: graduate, get a steady job, don't spend money unnecessarily e.g. don't keep upgrading your lifestyle/holidays/cars/shopping as your income increases, save money, find a good investment opportunity within budget, don't be afraid to invest. Maintain a good credit rating, this enabled us to get loans for property investments. Throughout it all, don't over-stretch your budget, ensure u are financially strong enough and cater for the event where there is no rental income for a few months.

The more spectacularly successful forumers can probably advise you better.

However considering the rather average salary of my spouse and I, we are doing alright though not fantastic. The more you can earn, the more disposable income you have for investments, the better you could do. I do admire those who have such high income, their life must be so comfortable. Good luck.