Your questions are far too big to generate meaningful replies, IMHO. There is no single strategy that's "the best"; fortunately there are many ways to profit from property investing.
Perhaps a couple of my blogs will help you refine what you want to do, such as
"How active or passive do you want to be?" and
"Developing the right property investing strategy for your circumstances".
Maybe after reading and considering those, you can come on with a more focused question, such as:
"I'd like to accumulate a portfolio of houses in the lower price range, in areas that I believe will gentrify and thus undergo significant growth over the next 20 years. I'm thinking of initially focusing on either suburb A area of Sydney, or suburb B area of western Melbourne, and would appreciate your thoughts as to the future prospects of these areas."
You need to ask a question specifically about finance, or about analysing deals, or about selecting areas to target, etc.
You can make a profit buying almost anywhere, long term. More important than picking the right market, is picking
a market and getting to know it well. This will enable you to readily spot good deals within that market. Choose somewhere, then start looking at all the listings, going to OFIs, studying statistics on growth, etc.
Your question, as it is now, is really so broad that it reads "somebody tell me what to buy and when so that I can get rich", and sorry, but nobody lays it out like that for you. And if they do, be highly suspicious - they're probably selling you over-priced property on a hefty commission!