First - buy in a rising market.
Try to select a country or region where property prices are rising. A totally obvious statement, but this underpins most successful investment plans. It just makes everything easier.
People who buy in flat markets to make money have to work a lot harder to find property that is valued below the market price because it is less visible and so has been overlooked.
People who buy in falling markets must have motives other than making money.
Rising markets are driven upwards by demand exceeding supply. This usually happens in the early stages of the market